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[proxmark3-svn] / armsrc / iso14443a.c
index ba4e6cf4d6128a777d457b1a4c71ba0940e770ab..27574dad2601cceda2f59b785445a1915a958892 100644 (file)
 #include "iso14443a.h"
 #include "crapto1.h"
 #include "mifareutil.h"
-
+#include "BigBuf.h"
 static uint32_t iso14a_timeout;
-uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
-int traceLen = 0;
 int rsamples = 0;
-int tracing = TRUE;
 uint8_t trigger = 0;
 // the block number for the ISO14443-4 PCB
 static uint8_t iso14_pcb_blocknum = 0;
 
+//
+// ISO14443 timing:
+//
+// minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
+#define REQUEST_GUARD_TIME (7000/16 + 1)
+// minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles 
+#define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1) 
+// bool LastCommandWasRequest = FALSE;
+
+//
+// Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
+//
+// When the PM acts as reader and is receiving tag data, it takes
+// 3 ticks delay in the AD converter
+// 16 ticks until the modulation detector completes and sets curbit
+// 8 ticks until bit_to_arm is assigned from curbit
+// 8*16 ticks for the transfer from FPGA to ARM
+// 4*16 ticks until we measure the time
+// - 8*16 ticks because we measure the time of the previous transfer 
+#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16) 
+
+// When the PM acts as a reader and is sending, it takes
+// 4*16 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks until the first transfer starts
+// 8 ticks later the FPGA samples the data
+// 1 tick to assign mod_sig_coil
+#define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
+
+// When the PM acts as tag and is receiving it takes
+// 2 ticks delay in the RF part (for the first falling edge),
+// 3 ticks for the A/D conversion,
+// 8 ticks on average until the start of the SSC transfer,
+// 8 ticks until the SSC samples the first data
+// 7*16 ticks to complete the transfer from FPGA to ARM
+// 8 ticks until the next ssp_clk rising edge
+// 4*16 ticks until we measure the time 
+// - 8*16 ticks because we measure the time of the previous transfer 
+#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
+// The FPGA will report its internal sending delay in
+uint16_t FpgaSendQueueDelay;
+// the 5 first bits are the number of bits buffered in mod_sig_buf
+// the last three bits are the remaining ticks/2 after the mod_sig_buf shift
+#define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
+
+// When the PM acts as tag and is sending, it takes
+// 4*16 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks until the first transfer starts
+// 8 ticks later the FPGA samples the data
+// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
+// + 1 tick to assign mod_sig_coil
+#define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
+
+// When the PM acts as sniffer and is receiving tag data, it takes
+// 3 ticks A/D conversion
+// 14 ticks to complete the modulation detection
+// 8 ticks (on average) until the result is stored in to_arm
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8) 
+// When the PM acts as sniffer and is receiving reader data, it takes
+// 2 ticks delay in analogue RF receiver (for the falling edge of the 
+// start bit, which marks the start of the communication)
+// 3 ticks A/D conversion
+// 8 ticks on average until the data is stored in to_arm.
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8) 
+
+//variables used for timing purposes:
+//these are in ssp_clk cycles:
+static uint32_t NextTransferTime;
+static uint32_t LastTimeProxToAirStart;
+static uint32_t LastProxToAirDuration;
+
+
+
 // CARD TO READER - manchester
 // Sequence D: 11110000 modulation with subcarrier during first half
 // Sequence E: 00001111 modulation with subcarrier during second half
@@ -69,19 +146,35 @@ void iso14a_set_trigger(bool enable) {
        trigger = enable;
 }
 
-void iso14a_clear_trace() {
-  memset(trace, 0x44, TRACE_SIZE);
-       traceLen = 0;
-}
-
-void iso14a_set_tracing(bool enable) {
-       tracing = enable;
-}
 
 void iso14a_set_timeout(uint32_t timeout) {
        iso14a_timeout = timeout;
+       if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 }
 
+
+void iso14a_set_ATS_timeout(uint8_t *ats) {
+
+       uint8_t tb1;
+       uint8_t fwi; 
+       uint32_t fwt;
+       
+       if (ats[0] > 1) {                                                       // there is a format byte T0
+               if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
+                       if ((ats[1] & 0x10) == 0x10) {          // there is an interface byte TA(1) preceding TB(1)
+                               tb1 = ats[3];
+                       } else {
+                               tb1 = ats[2];
+                       }
+                       fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
+                       fwt = 256 * 16 * (1 << fwi);            // frame waiting time (FWT) in 1/fc
+                       
+                       iso14a_set_timeout(fwt/(8*16));
+               }
+       }
+}
+
+
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //
@@ -91,17 +184,28 @@ byte_t oddparity (const byte_t bt)
        return OddByteParity[bt];
 }
 
-uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
+void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
 {
-       int i;
-       uint32_t dwPar = 0;
-
-       // Generate the parity bits
-       for (i = 0; i < iLen; i++) {
-               // and save them to a 32Bit word
-               dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
+       uint16_t paritybit_cnt = 0;
+       uint16_t paritybyte_cnt = 0;
+       uint8_t parityBits = 0;
+
+       for (uint16_t i = 0; i < iLen; i++) {
+               // Generate the parity bits
+               parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt));
+               if (paritybit_cnt == 7) {
+                       par[paritybyte_cnt] = parityBits;       // save 8 Bits parity
+                       parityBits = 0;                                         // and advance to next Parity Byte
+                       paritybyte_cnt++;
+                       paritybit_cnt = 0;
+               } else {
+                       paritybit_cnt++;
+               }
        }
-       return dwPar;
+
+       // save remaining parity bits
+       par[paritybyte_cnt] = parityBits;
+       
 }
 
 void AppendCrc14443a(uint8_t* data, int len)
@@ -109,275 +213,192 @@ void AppendCrc14443a(uint8_t* data, int len)
        ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 }
 
-// The function LogTrace() is also used by the iClass implementation in iClass.c
-int RAMFUNC LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader)
+void AppendCrc14443b(uint8_t* data, int len)
 {
-  // Return when trace is full
-  if (traceLen >= TRACE_SIZE) return FALSE;
-
-  // Trace the random, i'm curious
-  rsamples += iSamples;
-  trace[traceLen++] = ((rsamples >> 0) & 0xff);
-  trace[traceLen++] = ((rsamples >> 8) & 0xff);
-  trace[traceLen++] = ((rsamples >> 16) & 0xff);
-  trace[traceLen++] = ((rsamples >> 24) & 0xff);
-  if (!bReader) {
-    trace[traceLen - 1] |= 0x80;
-  }
-  trace[traceLen++] = ((dwParity >> 0) & 0xff);
-  trace[traceLen++] = ((dwParity >> 8) & 0xff);
-  trace[traceLen++] = ((dwParity >> 16) & 0xff);
-  trace[traceLen++] = ((dwParity >> 24) & 0xff);
-  trace[traceLen++] = iLen;
-  memcpy(trace + traceLen, btBytes, iLen);
-  traceLen += iLen;
-  return TRUE;
+       ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
 }
 
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
+
+//=============================================================================
+// ISO 14443 Type A - Miller decoder
+//=============================================================================
+// Basics:
+// This decoder is used when the PM3 acts as a tag.
+// The reader will generate "pauses" by temporarily switching of the field. 
+// At the PM3 antenna we will therefore measure a modulated antenna voltage. 
+// The FPGA does a comparison with a threshold and would deliver e.g.:
+// ........  1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1  .......
+// The Miller decoder needs to identify the following sequences:
+// 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated:        pause at beginning - Sequence Z ("start of communication" or a "0")
+// 8 ticks without a modulation:                                                                       no pause - Sequence Y (a "0" or "end of communication" or "no information")
+// 4 ticks unmodulated followed by 2 (or 3) ticks pause:                       pause in second half - Sequence X (a "1")
+// Note 1: the bitstream may start at any time. We therefore need to sync.
+// Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
 //-----------------------------------------------------------------------------
 static tUart Uart;
 
-static RAMFUNC int MillerDecoding(int bit)
-{
-       //int error = 0;
-       int bitright;
-
-       if(!Uart.bitBuffer) {
-               Uart.bitBuffer = bit ^ 0xFF0;
-               return FALSE;
-       }
-       else {
-               Uart.bitBuffer <<= 4;
-               Uart.bitBuffer ^= bit;
-       }
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept the following:
+// 0001  -   a 3 tick wide pause
+// 0011  -   a 2 tick wide pause, or a three tick wide pause shifted left
+// 0111  -   a 2 tick wide pause shifted left
+// 1001  -   a 2 tick wide pause shifted right
+const bool Mod_Miller_LUT[] = {
+       FALSE,  TRUE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,
+       FALSE,  TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
+};
+#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
+#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
 
-       int EOC = FALSE;
+void UartReset()
+{
+       Uart.state = STATE_UNSYNCD;
+       Uart.bitCount = 0;
+       Uart.len = 0;                                           // number of decoded data bytes
+       Uart.parityLen = 0;                                     // number of decoded parity bytes
+       Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
+       Uart.parityBits = 0;                            // holds 8 parity bits
+       Uart.startTime = 0;
+       Uart.endTime = 0;
+}
 
-       if(Uart.state != STATE_UNSYNCD) {
-               Uart.posCnt++;
+void UartInit(uint8_t *data, uint8_t *parity)
+{
+       Uart.output = data;
+       Uart.parity = parity;
+       Uart.fourBits = 0x00000000;                     // clear the buffer for 4 Bits
+       UartReset();
+}
 
-               if((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit) {
-                       bit = 0x00;
-               }
-               else {
-                       bit = 0x01;
-               }
-               if(((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit) {
-                       bitright = 0x00;
-               }
-               else {
-                       bitright = 0x01;
-               }
-               if(bit != bitright) { bit = bitright; }
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
+{
 
-               if(Uart.posCnt == 1) {
-                       // measurement first half bitperiod
-                       if(!bit) {
-                               Uart.drop = DROP_FIRST_HALF;
-                       }
+       Uart.fourBits = (Uart.fourBits << 8) | bit;
+       
+       if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
+       
+               Uart.syncBit = 9999;                                                                                                    // not set
+               // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
+               // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
+               // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern 
+               // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
+               #define ISO14443A_STARTBIT_MASK         0x07FFEF80                                                      // mask is    00000111 11111111 11101111 10000000
+               #define ISO14443A_STARTBIT_PATTERN      0x07FF8F80                                                      // pattern is 00000111 11111111 10001111 10000000
+               if              ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
+               else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
+
+               if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
+                       Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+                       Uart.startTime -= Uart.syncBit;
+                       Uart.endTime = Uart.startTime;
+                       Uart.state = STATE_START_OF_COMMUNICATION;
                }
-               else {
-                       // measurement second half bitperiod
-                       if(!bit & (Uart.drop == DROP_NONE)) {
-                               Uart.drop = DROP_SECOND_HALF;
-                       }
-                       else if(!bit) {
-                               // measured a drop in first and second half
-                               // which should not be possible
-                               Uart.state = STATE_ERROR_WAIT;
-                               //error = 0x01;
-                       }
-
-                       Uart.posCnt = 0;
-
-                       switch(Uart.state) {
-                               case STATE_START_OF_COMMUNICATION:
-                                       Uart.shiftReg = 0;
-                                       if(Uart.drop == DROP_SECOND_HALF) {
-                                               // error, should not happen in SOC
-                                               Uart.state = STATE_ERROR_WAIT;
-                                               //error = 0x02;
-                                       }
-                                       else {
-                                               // correct SOC
-                                               Uart.state = STATE_MILLER_Z;
-                                       }
-                                       break;
 
-                               case STATE_MILLER_Z:
-                                       Uart.bitCnt++;
-                                       Uart.shiftReg >>= 1;
-                                       if(Uart.drop == DROP_NONE) {
-                                               // logic '0' followed by sequence Y
-                                               // end of communication
-                                               Uart.state = STATE_UNSYNCD;
-                                               EOC = TRUE;
-                                       }
-                                       // if(Uart.drop == DROP_FIRST_HALF) {
-                                       //      Uart.state = STATE_MILLER_Z; stay the same
-                                       //      we see a logic '0' }
-                                       if(Uart.drop == DROP_SECOND_HALF) {
-                                               // we see a logic '1'
-                                               Uart.shiftReg |= 0x100;
-                                               Uart.state = STATE_MILLER_X;
-                                       }
-                                       break;
-
-                               case STATE_MILLER_X:
-                                       Uart.shiftReg >>= 1;
-                                       if(Uart.drop == DROP_NONE) {
-                                               // sequence Y, we see a '0'
-                                               Uart.state = STATE_MILLER_Y;
-                                               Uart.bitCnt++;
-                                       }
-                                       if(Uart.drop == DROP_FIRST_HALF) {
-                                               // Would be STATE_MILLER_Z
-                                               // but Z does not follow X, so error
-                                               Uart.state = STATE_ERROR_WAIT;
-                                               //error = 0x03;
-                                       }
-                                       if(Uart.drop == DROP_SECOND_HALF) {
-                                               // We see a '1' and stay in state X
-                                               Uart.shiftReg |= 0x100;
-                                               Uart.bitCnt++;
-                                       }
-                                       break;
+       } else {
 
-                               case STATE_MILLER_Y:
-                                       Uart.bitCnt++;
-                                       Uart.shiftReg >>= 1;
-                                       if(Uart.drop == DROP_NONE) {
-                                               // logic '0' followed by sequence Y
-                                               // end of communication
-                                               Uart.state = STATE_UNSYNCD;
-                                               EOC = TRUE;
+               if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {                 
+                       if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
+                               UartReset();
+                       } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
+                               if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
+                                       UartReset();
+                               } else {
+                                       Uart.bitCount++;
+                                       Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
+                                       Uart.state = STATE_MILLER_Z;
+                                       Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
+                                       if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
+                                               Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+                                               Uart.parityBits <<= 1;                                                                  // make room for the parity bit
+                                               Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
+                                               Uart.bitCount = 0;
+                                               Uart.shiftReg = 0;
+                                               if((Uart.len&0x0007) == 0) {                                                    // every 8 data bytes
+                                                       Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
+                                                       Uart.parityBits = 0;
+                                               }
                                        }
-                                       if(Uart.drop == DROP_FIRST_HALF) {
-                                               // we see a '0'
-                                               Uart.state = STATE_MILLER_Z;
+                               }
+                       }
+               } else {
+                       if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
+                               Uart.bitCount++;
+                               Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
+                               Uart.state = STATE_MILLER_X;
+                               Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
+                               if(Uart.bitCount >= 9) {                                                                                // if we decoded a full byte (including parity)
+                                       Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+                                       Uart.parityBits <<= 1;                                                                          // make room for the new parity bit
+                                       Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);                       // store parity bit
+                                       Uart.bitCount = 0;
+                                       Uart.shiftReg = 0;
+                                       if ((Uart.len&0x0007) == 0) {                                                           // every 8 data bytes
+                                               Uart.parity[Uart.parityLen++] = Uart.parityBits;                // store 8 parity bits
+                                               Uart.parityBits = 0;
                                        }
-                                       if(Uart.drop == DROP_SECOND_HALF) {
-                                               // We see a '1' and go to state X
-                                               Uart.shiftReg |= 0x100;
-                                               Uart.state = STATE_MILLER_X;
+                               }
+                       } else {                                                                                                                        // no modulation in both halves - Sequence Y
+                               if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {     // Y after logic "0" - End of Communication
+                                       Uart.state = STATE_UNSYNCD;
+                                       Uart.bitCount--;                                                                                        // last "0" was part of EOC sequence
+                                       Uart.shiftReg <<= 1;                                                                            // drop it
+                                       if(Uart.bitCount > 0) {                                                                         // if we decoded some bits
+                                               Uart.shiftReg >>= (9 - Uart.bitCount);                                  // right align them
+                                               Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);               // add last byte to the output
+                                               Uart.parityBits <<= 1;                                                                  // add a (void) parity bit
+                                               Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align parity bits
+                                               Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store it
+                                               return TRUE;
+                                       } else if (Uart.len & 0x0007) {                                                         // there are some parity bits to store
+                                               Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align remaining parity bits
+                                               Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store them
                                        }
-                                       break;
-
-                               case STATE_ERROR_WAIT:
-                                       // That went wrong. Now wait for at least two bit periods
-                                       // and try to sync again
-                                       if(Uart.drop == DROP_NONE) {
-                                               Uart.highCnt = 6;
-                                               Uart.state = STATE_UNSYNCD;
+                                       if (Uart.len) {
+                                               return TRUE;                                                                                    // we are finished with decoding the raw data sequence
+                                       } else {
+                                               UartReset();                                                                                    // Nothing received - start over
                                        }
-                                       break;
-
-                               default:
-                                       Uart.state = STATE_UNSYNCD;
-                                       Uart.highCnt = 0;
-                                       break;
-                       }
-
-                       Uart.drop = DROP_NONE;
-
-                       // should have received at least one whole byte...
-                       if((Uart.bitCnt == 2) && EOC && (Uart.byteCnt > 0)) {
-                               return TRUE;
-                       }
-
-                       if(Uart.bitCnt == 9) {
-                               Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
-                               Uart.byteCnt++;
-
-                               Uart.parityBits <<= 1;
-                               Uart.parityBits ^= ((Uart.shiftReg >> 8) & 0x01);
-
-                               if(EOC) {
-                                       // when End of Communication received and
-                                       // all data bits processed..
-                                       return TRUE;
                                }
-                               Uart.bitCnt = 0;
-                       }
-
-                       /*if(error) {
-                               Uart.output[Uart.byteCnt] = 0xAA;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = error & 0xFF;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = 0xAA;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = (Uart.bitBuffer >> 8) & 0xFF;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = (Uart.syncBit >> 3) & 0xFF;
-                               Uart.byteCnt++;
-                               Uart.output[Uart.byteCnt] = 0xAA;
-                               Uart.byteCnt++;
-                               return TRUE;
-                       }*/
-               }
-
-       }
-       else {
-               bit = Uart.bitBuffer & 0xf0;
-               bit >>= 4;
-               bit ^= 0x0F;
-               if(bit) {
-                       // should have been high or at least (4 * 128) / fc
-                       // according to ISO this should be at least (9 * 128 + 20) / fc
-                       if(Uart.highCnt == 8) {
-                               // we went low, so this could be start of communication
-                               // it turns out to be safer to choose a less significant
-                               // syncbit... so we check whether the neighbour also represents the drop
-                               Uart.posCnt = 1;   // apparently we are busy with our first half bit period
-                               Uart.syncBit = bit & 8;
-                               Uart.samples = 3;
-                               if(!Uart.syncBit)       { Uart.syncBit = bit & 4; Uart.samples = 2; }
-                               else if(bit & 4)        { Uart.syncBit = bit & 4; Uart.samples = 2; bit <<= 2; }
-                               if(!Uart.syncBit)       { Uart.syncBit = bit & 2; Uart.samples = 1; }
-                               else if(bit & 2)        { Uart.syncBit = bit & 2; Uart.samples = 1; bit <<= 1; }
-                               if(!Uart.syncBit)       { Uart.syncBit = bit & 1; Uart.samples = 0;
-                                       if(Uart.syncBit && (Uart.bitBuffer & 8)) {
-                                               Uart.syncBit = 8;
-
-                                               // the first half bit period is expected in next sample
-                                               Uart.posCnt = 0;
-                                               Uart.samples = 3;
+                               if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
+                                       UartReset();
+                               } else {                                                                                                                // a logic "0"
+                                       Uart.bitCount++;
+                                       Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
+                                       Uart.state = STATE_MILLER_Y;
+                                       if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
+                                               Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+                                               Uart.parityBits <<= 1;                                                                  // make room for the parity bit
+                                               Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
+                                               Uart.bitCount = 0;
+                                               Uart.shiftReg = 0;
+                                               if ((Uart.len&0x0007) == 0) {                                                   // every 8 data bytes
+                                                       Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
+                                                       Uart.parityBits = 0;
+                                               }
                                        }
                                }
-                               else if(bit & 1)        { Uart.syncBit = bit & 1; Uart.samples = 0; }
-
-                               Uart.syncBit <<= 4;
-                               Uart.state = STATE_START_OF_COMMUNICATION;
-                               Uart.drop = DROP_FIRST_HALF;
-                               Uart.bitCnt = 0;
-                               Uart.byteCnt = 0;
-                               Uart.parityBits = 0;
-                               //error = 0;
-                       }
-                       else {
-                               Uart.highCnt = 0;
-                       }
-               }
-               else {
-                       if(Uart.highCnt < 8) {
-                               Uart.highCnt++;
                        }
                }
-       }
+                       
+       } 
 
-    return FALSE;
+    return FALSE;      // not finished yet, need more data
 }
 
+
+
 //=============================================================================
 // ISO 14443 Type A - Manchester decoder
 //=============================================================================
 // Basics:
+// This decoder is used when the PM3 acts as a reader.
 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
 // ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .......
@@ -386,161 +407,131 @@ static RAMFUNC int MillerDecoding(int bit)
 // 4 ticks unmodulated followed by 4 ticks modulated:  Sequence E = 0
 // 8 ticks unmodulated:                                                                        Sequence F = end of communication
 // 8 ticks modulated:                                                                  A collision. Save the collision position and treat as Sequence D
-// Note 1: the bitstream may start at any time (either in first or second nibble within the parameter bit). We therefore need to sync.
+// Note 1: the bitstream may start at any time. We therefore need to sync.
 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 static tDemod Demod;
 
-inline RAMFUNC bool IsModulation(byte_t b)
-{
-       if (b >= 5 || b == 3)           // majority decision: 2 or more bits are set
-               return true;
-       else
-               return false;
-       
-}
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept three or four "1" in any position
+const bool Mod_Manchester_LUT[] = {
+       FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
+       FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
+};
+
+#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
+#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
 
-inline RAMFUNC bool IsModulationNibble1(byte_t b)
+
+void DemodReset()
 {
-       return IsModulation((b & 0xE0) >> 5);
+       Demod.state = DEMOD_UNSYNCD;
+       Demod.len = 0;                                          // number of decoded data bytes
+       Demod.parityLen = 0;
+       Demod.shiftReg = 0;                                     // shiftreg to hold decoded data bits
+       Demod.parityBits = 0;                           // 
+       Demod.collisionPos = 0;                         // Position of collision bit
+       Demod.twoBits = 0xffff;                         // buffer for 2 Bits
+       Demod.highCnt = 0;
+       Demod.startTime = 0;
+       Demod.endTime = 0;
 }
 
-inline RAMFUNC bool IsModulationNibble2(byte_t b)
+void DemodInit(uint8_t *data, uint8_t *parity)
 {
-       return IsModulation((b & 0x0E) >> 1);
+       Demod.output = data;
+       Demod.parity = parity;
+       DemodReset();
 }
 
-static RAMFUNC int ManchesterDecoding(int bit, uint16_t offset)
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
 {
+
+       Demod.twoBits = (Demod.twoBits << 8) | bit;
        
-       switch (Demod.state) {
-
-               case DEMOD_UNSYNCD:                                             // not yet synced
-                       Demod.len = 0;                                          // initialize number of decoded data bytes
-                       Demod.bitCount = offset;                        // initialize number of decoded data bits
-                       Demod.shiftReg = 0;                                     // initialize shiftreg to hold decoded data bits
-                       Demod.parityBits = 0;                           // initialize parity bits
-                       Demod.collisionPos = 0;                         // Position of collision bit
-                       
-                       if (IsModulationNibble1(bit) 
-                               && !IsModulationNibble2(bit)) {                                                         // this is the start bit
-                               Demod.samples = 8;
-                               if(trigger) LED_A_OFF();
+       if (Demod.state == DEMOD_UNSYNCD) {
+
+               if (Demod.highCnt < 2) {                                                                                        // wait for a stable unmodulated signal
+                       if (Demod.twoBits == 0x0000) {
+                               Demod.highCnt++;
+                       } else {
+                               Demod.highCnt = 0;
+                       }
+               } else {
+                       Demod.syncBit = 0xFFFF;                 // not set
+                       if              ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7; 
+                       else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
+                       else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
+                       else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
+                       else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
+                       else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
+                       else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
+                       else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
+                       if (Demod.syncBit != 0xFFFF) {
+                               Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+                               Demod.startTime -= Demod.syncBit;
+                               Demod.bitCount = offset;                        // number of decoded data bits
                                Demod.state = DEMOD_MANCHESTER_DATA;
-                       } else if (!IsModulationNibble1(bit) && IsModulationNibble2(bit)) { // this may be the first half of the start bit
-                                       Demod.samples = 4;
-                                       Demod.state = DEMOD_HALF_SYNCD;
                        }
-                       break;
+               }
 
+       } else {
 
-               case DEMOD_HALF_SYNCD:
-                       Demod.samples += 8;
-                       if (IsModulationNibble1(bit)) {                                                         // error: this was not a start bit.
-                               Demod.state = DEMOD_UNSYNCD;
-                       } else {
-                               if (IsModulationNibble2(bit)) {                                                 // modulation in first half
-                                       Demod.state = DEMOD_MOD_FIRST_HALF;
-                               } else {                                                                                                // no modulation in first half
-                                       Demod.state = DEMOD_NOMOD_FIRST_HALF;
-                               }
-                       }
-                       break;
-                       
-                       
-               case DEMOD_MOD_FIRST_HALF:
-                       Demod.samples += 8;
-                       Demod.bitCount++;
-                       if (IsModulationNibble1(bit)) {                                                         // modulation in both halfs - collision
+               if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {            // modulation in first half
+                       if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // ... and in second half = collision
                                if (!Demod.collisionPos) {
                                        Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
                                }
                        }                                                                                                                       // modulation in first half only - Sequence D = 1
-                       Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // add a 1 to the shiftreg
-                       if(Demod.bitCount >= 9) {                                                                       // if we decoded a full byte (including parity)
-                               Demod.parityBits <<= 1;                                                                 // make room for the parity bit
+                       Demod.bitCount++;
+                       Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // in both cases, add a 1 to the shiftreg
+                       if(Demod.bitCount == 9) {                                                                       // if we decoded a full byte (including parity)
                                Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+                               Demod.parityBits <<= 1;                                                                 // make room for the parity bit
                                Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01);     // store parity bit
                                Demod.bitCount = 0;
                                Demod.shiftReg = 0;
+                               if((Demod.len&0x0007) == 0) {                                                   // every 8 data bytes
+                                       Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits
+                                       Demod.parityBits = 0;
+                               }
                        }
-                       if (IsModulationNibble2(bit)) {                                                         // modulation in first half
-                               Demod.state = DEMOD_MOD_FIRST_HALF;
-                       } else {                                                                                                        // no modulation in first half
-                               Demod.state = DEMOD_NOMOD_FIRST_HALF;
-                       }
-                       break;
-
-
-               case DEMOD_NOMOD_FIRST_HALF:
-                       if (IsModulationNibble1(bit)) {                                                         // modulation in second half only - Sequence E = 0
+                       Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
+               } else {                                                                                                                // no modulation in first half
+                       if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // and modulation in second half = Sequence E = 0
                                Demod.bitCount++;
-                               Demod.samples += 8;
-                               Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
+                               Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
                                if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
-                                       Demod.parityBits <<= 1;                                                         // make room for the new parity bit
                                        Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+                                       Demod.parityBits <<= 1;                                                         // make room for the new parity bit
                                        Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
                                        Demod.bitCount = 0;
                                        Demod.shiftReg = 0;
+                                       if ((Demod.len&0x0007) == 0) {                                          // every 8 data bytes
+                                               Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits1
+                                               Demod.parityBits = 0;
+                                       }
                                }
+                               Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
                        } else {                                                                                                        // no modulation in both halves - End of communication
-                               Demod.samples += 4;
-                               if(Demod.bitCount > 0) {                                                                // if we decoded bits
-                                       Demod.shiftReg >>= (9 - Demod.bitCount);                        // add the remaining decoded bits to the output
-                                       Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
-                                       // No parity bit, so just shift a 0
-                                       Demod.parityBits <<= 1;
-                               }
-                               Demod.state = DEMOD_UNSYNCD;                                                    // start from the beginning
-                               return TRUE;                                                                                    // we are finished with decoding the raw data sequence
-                       }
-                       if (IsModulationNibble2(bit)) {                                                         // modulation in first half
-                               Demod.state = DEMOD_MOD_FIRST_HALF;
-                       } else {                                                                                                        // no modulation in first half
-                               Demod.state = DEMOD_NOMOD_FIRST_HALF;
-                       }
-                       break;
-                       
-
-               case DEMOD_MANCHESTER_DATA:
-                       Demod.samples += 8;
-                       if (IsModulationNibble1(bit)) {                                                                 // modulation in first half
-                               if (IsModulationNibble2(bit) & 0x0f) {                                          // ... and in second half = collision
-                                       if (!Demod.collisionPos) {
-                                               Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
-                                       }
-                               }                                                                                                               // modulation in first half only - Sequence D = 1
-                               Demod.bitCount++;
-                               Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                 // in both cases, add a 1 to the shiftreg
-                               if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
-                                       Demod.parityBits <<= 1;                                                         // make room for the parity bit
-                                       Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
-                                       Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
-                                       Demod.bitCount = 0;
-                                       Demod.shiftReg = 0;
+                               if(Demod.bitCount > 0) {                                                                // there are some remaining data bits
+                                       Demod.shiftReg >>= (9 - Demod.bitCount);                        // right align the decoded bits
+                                       Demod.output[Demod.len++] = Demod.shiftReg & 0xff;      // and add them to the output
+                                       Demod.parityBits <<= 1;                                                         // add a (void) parity bit
+                                       Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
+                                       Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
+                                       return TRUE;
+                               } else if (Demod.len & 0x0007) {                                                // there are some parity bits to store
+                                       Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
+                                       Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
                                }
-                       } else {                                                                                                        // no modulation in first half
-                               if (IsModulationNibble2(bit)) {                                                 // and modulation in second half = Sequence E = 0
-                                       Demod.bitCount++;
-                                       Demod.shiftReg = (Demod.shiftReg >> 1);                         // add a 0 to the shiftreg
-                                       if(Demod.bitCount >= 9) {                                                       // if we decoded a full byte (including parity)
-                                               Demod.parityBits <<= 1;                                                 // make room for the new parity bit
-                                               Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
-                                               Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
-                                               Demod.bitCount = 0;
-                                               Demod.shiftReg = 0;
-                                       }
-                               } else {                                                                                                // no modulation in both halves - End of communication
-                                       if(Demod.bitCount > 0) {                                                        // if we decoded bits
-                                               Demod.shiftReg >>= (9 - Demod.bitCount);                // add the remaining decoded bits to the output
-                                               Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
-                                               // No parity bit, so just shift a 0
-                                               Demod.parityBits <<= 1;
-                                       }
-                                       Demod.state = DEMOD_UNSYNCD;                                            // start from the beginning
+                               if (Demod.len) {
                                        return TRUE;                                                                            // we are finished with decoding the raw data sequence
+                               } else {                                                                                                // nothing received. Start over
+                                       DemodReset();
                                }
                        }
+               }
                        
        } 
 
@@ -563,61 +554,56 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
        // bit 1 - trigger from first reader 7-bit request
        
        LEDsoff();
-       // init trace buffer
-       iso14a_clear_trace();
 
-       // We won't start recording the frames that we acquire until we trigger;
-       // a good trigger condition to get started is probably when we see a
-       // response from the tag.
-       // triggered == FALSE -- to wait first for card
-       int triggered = !(param & 0x03); 
+       iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
+       // Allocate memory from BigBuf for some buffers
+       // free all previous allocations first
+       BigBuf_free();
 
        // The command (reader -> tag) that we're receiving.
-       // The length of a received command will in most cases be no more than 18 bytes.
-       // So 32 should be enough!
-       uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+       uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+       uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
+       
        // The response (tag -> reader) that we're receiving.
-       uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
-
-       // As we receive stuff, we copy it from receivedCmd or receivedResponse
-       // into trace, along with its length and other annotations.
-       //uint8_t *trace = (uint8_t *)BigBuf;
+       uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
+       uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
        
        // The DMA buffer, used to stream samples from the FPGA
-       int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
-       int8_t *data = dmaBuf;
+       uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
+
+       // init trace buffer
+       clear_trace();
+       set_tracing(TRUE);
+
+       uint8_t *data = dmaBuf;
+       uint8_t previous_data = 0;
        int maxDataLen = 0;
        int dataLen = 0;
-
+       bool TagIsActive = FALSE;
+       bool ReaderIsActive = FALSE;
+       
        // Set up the demodulator for tag -> reader responses.
-       Demod.output = receivedResponse;
-       Demod.len = 0;
-       Demod.state = DEMOD_UNSYNCD;
-
+       DemodInit(receivedResponse, receivedResponsePar);
+       
        // Set up the demodulator for the reader -> tag commands
-       memset(&Uart, 0, sizeof(Uart));
-       Uart.output = receivedCmd;
-       Uart.byteCntMax = 32;                        // was 100 (greg)//////////////////
-       Uart.state = STATE_UNSYNCD;
-
-       // Setup for the DMA.
-       FpgaSetupSsc();
+       UartInit(receivedCmd, receivedCmdPar);
+       
+       // Setup and start DMA.
        FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
-
-       // And put the FPGA in the appropriate mode
-       // Signal field is off with the appropriate LED
-       LED_D_OFF();
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
-       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-       // Count of samples received so far, so that we can include timing
-       // information in the trace buffer.
-       rsamples = 0;
+       
+       // We won't start recording the frames that we acquire until we trigger;
+       // a good trigger condition to get started is probably when we see a
+       // response from the tag.
+       // triggered == FALSE -- to wait first for card
+       bool triggered = !(param & 0x03); 
+       
        // And now we loop, receiving samples.
-       while(true) {
+       for(uint32_t rsamples = 0; TRUE; ) {
+
                if(BUTTON_PRESS()) {
                        DbpString("cancelled by button");
-                       goto done;
+                       break;
                }
 
                LED_A_ON();
@@ -628,14 +614,14 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
                if (readBufDataP <= dmaBufDataP){
                        dataLen = dmaBufDataP - readBufDataP;
                } else {
-                       dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
+                       dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
                }
                // test for length of buffer
                if(dataLen > maxDataLen) {
                        maxDataLen = dataLen;
-                       if(dataLen > 400) {
-                               Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
-                               goto done;
+                       if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
+                               Dbprintf("blew circular buffer! dataLen=%d", dataLen);
+                               break;
                        }
                }
                if(dataLen < 1) continue;
@@ -644,6 +630,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
                if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
                        AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
                        AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+                       Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
                }
                // secondary buffer sets as primary, secondary buffer was stopped
                if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
@@ -652,61 +639,81 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
                }
 
                LED_A_OFF();
-               if(MF_DBGLEVEL > 4) Dbprintf("1:%d",dataLen);
-               rsamples += 4;
-               if(MillerDecoding((data[0] & 0xF0) >> 4)) {
-                       LED_C_ON();
+               
+               if (rsamples & 0x01) {                          // Need two samples to feed Miller and Manchester-Decoder
+
+                       if(!TagIsActive) {              // no need to try decoding reader data if the tag is sending
+                               uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+                               if (MillerDecoding(readerdata, (rsamples-1)*4)) {
+                                       LED_C_ON();
+
+                                       // check - if there is a short 7bit request from reader
+                                       if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
+
+                                       if(triggered) {
+                                               if (!LogTrace(receivedCmd, 
+                                                                               Uart.len, 
+                                                                               Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
+                                                                               Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
+                                                                               Uart.parity, 
+                                                                               TRUE)) break;
+                                       }
+                                       /* And ready to receive another command. */
+                                       UartReset();
+                                       /* And also reset the demod code, which might have been */
+                                       /* false-triggered by the commands from the reader. */
+                                       DemodReset();
+                                       LED_B_OFF();
+                               }
+                               ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+                       }
 
-                       // check - if there is a short 7bit request from reader
-                       if ((!triggered) && (param & 0x02) && (Uart.byteCnt == 1) && (Uart.bitCnt = 9)) triggered = TRUE;
+                       if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
+                               uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+                               if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
+                                       LED_B_ON();
 
-                       if(triggered) {
-                               if (!LogTrace(receivedCmd, Uart.byteCnt, 0 - Uart.samples, Uart.parityBits, TRUE)) break;
-                       }
-                       /* And ready to receive another command. */
-                       Uart.state = STATE_UNSYNCD;
-                       /* And also reset the demod code, which might have been */
-                       /* false-triggered by the commands from the reader. */
-                       Demod.state = DEMOD_UNSYNCD;
-                       LED_B_OFF();
-               }
-               if(MF_DBGLEVEL > 4) Dbprintf("2");
-               if(ManchesterDecoding(data[0], 0)) {
-                       LED_B_ON();
+                                       if (!LogTrace(receivedResponse, 
+                                                                       Demod.len, 
+                                                                       Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, 
+                                                                       Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
+                                                                       Demod.parity,
+                                                                       FALSE)) break;
 
-                       if (!LogTrace(receivedResponse, Demod.len, 0 - Demod.samples, Demod.parityBits, FALSE)) break;
+                                       if ((!triggered) && (param & 0x01)) triggered = TRUE;
 
-                       if ((!triggered) && (param & 0x01)) triggered = TRUE;
+                                       // And ready to receive another response.
+                                       DemodReset();
+                                       // And reset the Miller decoder including itS (now outdated) input buffer
+                                       UartInit(receivedCmd, receivedCmdPar);
 
-                       // And ready to receive another response.
-                       memset(&Demod, 0, sizeof(Demod));
-                       Demod.output = receivedResponse;
-                       Demod.state = DEMOD_UNSYNCD;
-                       LED_C_OFF();
+                                       LED_C_OFF();
+                               } 
+                               TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+                       }
                }
 
+               previous_data = *data;
+               rsamples++;
                data++;
-               if(data > dmaBuf + DMA_BUFFER_SIZE) {
+               if(data == dmaBuf + DMA_BUFFER_SIZE) {
                        data = dmaBuf;
                }
        } // main cycle
 
        DbpString("COMMAND FINISHED");
 
-done:
-       AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
-       Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x", maxDataLen, Uart.state, Uart.byteCnt);
-       Dbprintf("Uart.byteCntMax=%x, traceLen=%x, Uart.output[0]=%08x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+       FpgaDisableSscDma();
+       Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
+       Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
        LEDsoff();
 }
 
 //-----------------------------------------------------------------------------
 // Prepare tag messages
 //-----------------------------------------------------------------------------
-static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
+static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
 {
-       int i;
-
        ToSendReset();
 
        // Correction bit, might be removed when not needed
@@ -721,13 +728,13 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity
        
        // Send startbit
        ToSend[++ToSendMax] = SEC_D;
+       LastProxToAirDuration = 8 * ToSendMax - 4;
 
-       for(i = 0; i < len; i++) {
-               int j;
+       for(uint16_t i = 0; i < len; i++) {
                uint8_t b = cmd[i];
 
                // Data bits
-               for(j = 0; j < 8; j++) {
+               for(uint16_t j = 0; j < 8; j++) {
                        if(b & 1) {
                                ToSend[++ToSendMax] = SEC_D;
                        } else {
@@ -737,10 +744,12 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity
                }
 
                // Get the parity bit
-               if ((dwParity >> i) & 0x01) {
+               if (parity[i>>3] & (0x80>>(i&0x0007))) {
                        ToSend[++ToSendMax] = SEC_D;
+                       LastProxToAirDuration = 8 * ToSendMax - 4;
                } else {
                        ToSend[++ToSendMax] = SEC_E;
+                       LastProxToAirDuration = 8 * ToSendMax;
                }
        }
 
@@ -751,52 +760,14 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity
        ToSendMax++;
 }
 
-static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
-       CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
+static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
+{
+       uint8_t par[MAX_PARITY_SIZE];
+       
+       GetParity(cmd, len, par);
+       CodeIso14443aAsTagPar(cmd, len, par);
 }
 
-////-----------------------------------------------------------------------------
-//// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4
-////-----------------------------------------------------------------------------
-//static void CodeStrangeAnswerAsTag()
-//{
-//     int i;
-//
-//     ToSendReset();
-//
-//     // Correction bit, might be removed when not needed
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(1);  // 1
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(0);
-//     ToSendStuffBit(0);
-//
-//     // Send startbit
-//     ToSend[++ToSendMax] = SEC_D;
-//
-//     // 0
-//     ToSend[++ToSendMax] = SEC_E;
-//
-//     // 0
-//     ToSend[++ToSendMax] = SEC_E;
-//
-//     // 1
-//     ToSend[++ToSendMax] = SEC_D;
-//
-//     // Send stopbit
-//     ToSend[++ToSendMax] = SEC_F;
-//
-//     // Flush the buffer in FPGA!!
-//     for(i = 0; i < 5; i++) {
-//             ToSend[++ToSendMax] = SEC_F;
-//     }
-//
-//     // Convert from last byte pos to length
-//     ToSendMax++;
-//}
 
 static void Code4bitAnswerAsTag(uint8_t cmd)
 {
@@ -821,8 +792,10 @@ static void Code4bitAnswerAsTag(uint8_t cmd)
        for(i = 0; i < 4; i++) {
                if(b & 1) {
                        ToSend[++ToSendMax] = SEC_D;
+                       LastProxToAirDuration = 8 * ToSendMax - 4;
                } else {
                        ToSend[++ToSendMax] = SEC_E;
+                       LastProxToAirDuration = 8 * ToSendMax;
                }
                b >>= 1;
        }
@@ -830,11 +803,6 @@ static void Code4bitAnswerAsTag(uint8_t cmd)
        // Send stopbit
        ToSend[++ToSendMax] = SEC_F;
 
-       // Flush the buffer in FPGA!!
-       for(i = 0; i < 5; i++) {
-               ToSend[++ToSendMax] = SEC_F;
-       }
-
        // Convert from last byte pos to length
        ToSendMax++;
 }
@@ -844,7 +812,7 @@ static void Code4bitAnswerAsTag(uint8_t cmd)
 // Stop when button is pressed
 // Or return TRUE when command is captured
 //-----------------------------------------------------------------------------
-static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
+static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
 {
     // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
     // only, since we are receiving, not transmitting).
@@ -853,56 +821,48 @@ static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen
     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 
     // Now run a `software UART' on the stream of incoming samples.
-    Uart.output = received;
-    Uart.byteCntMax = maxLen;
-    Uart.state = STATE_UNSYNCD;
+       UartInit(received, parity);
+
+       // clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 
     for(;;) {
         WDT_HIT();
 
         if(BUTTON_PRESS()) return FALSE;
-
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = 0x00;
-        }
+               
         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       if(MillerDecoding((b & 0xf0) >> 4)) {
-                               *len = Uart.byteCnt;
+            b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       if(MillerDecoding(b, 0)) {
+                               *len = Uart.len;
                                return TRUE;
                        }
-                       if(MillerDecoding(b & 0x0f)) {
-                               *len = Uart.byteCnt;
-                               return TRUE;
-                       }
-        }
+               }
     }
 }
 
-static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded);
-int EmSend4bitEx(uint8_t resp, int correctionNeeded);
+static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
+int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
 int EmSend4bit(uint8_t resp);
-int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
-int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
-int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded);
-int EmSendCmd(uint8_t *resp, int respLen);
-int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
+int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
+int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
+int EmSendCmd(uint8_t *resp, uint16_t respLen);
+int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
+bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
+                                uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
 
-static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+static uint8_t* free_buffer_pointer;
 
 typedef struct {
   uint8_t* response;
   size_t   response_n;
   uint8_t* modulation;
   size_t   modulation_n;
+  uint32_t ProxToAirDuration;
 } tag_response_info_t;
 
-void reset_free_buffer() {
-  free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
-}
-
 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
-       // Exmaple response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
+       // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
        // This will need the following byte array for a modulation sequence
        //    144        data bits (18 * 8)
        //     18        parity bits
@@ -912,7 +872,8 @@ bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffe
        // ----------- +
        //    166 bytes, since every bit that needs to be send costs us a byte
        //
-  
   // Prepare the tag modulation bits from the message
   CodeIso14443aAsTag(response_info->response,response_info->response_n);
   
@@ -926,21 +887,29 @@ bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffe
   // Copy the byte array, used for this modulation to the buffer position
   memcpy(response_info->modulation,ToSend,ToSendMax);
   
-  // Store the number of bytes that were used for encoding/modulation
+  // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
   response_info->modulation_n = ToSendMax;
+  response_info->ProxToAirDuration = LastProxToAirDuration;
   
   return true;
 }
 
+
+// "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
+// Coded responses need one byte per bit to transfer (data, parity, start, stop, correction) 
+// 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
+// -> need 273 bytes buffer
+#define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273
+
 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
   // Retrieve and store the current buffer index
   response_info->modulation = free_buffer_pointer;
   
   // Determine the maximum size we can use from our buffer
-  size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
+  size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
   
   // Forward the prepare tag modulation function to the inner function
-  if (prepare_tag_modulation(response_info,max_buffer_size)) {
+  if (prepare_tag_modulation(response_info, max_buffer_size)) {
     // Update the free buffer offset
     free_buffer_pointer += ToSendMax;
     return true;
@@ -955,11 +924,6 @@ bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 //-----------------------------------------------------------------------------
 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
 {
-       // Enable and clear the trace
-       tracing = TRUE;
-       iso14a_clear_trace();
-
-       // This function contains the tag emulation
        uint8_t sak;
 
        // The first response contains the ATQA (note: bytes are transmitted in reverse order).
@@ -990,6 +954,12 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
                        response1[1] = 0x00;
                        sak = 0x28;
                } break;
+               case 5: { // MIFARE TNP3XXX
+                       // Says: I am a toy
+                       response1[0] = 0x01;
+                       response1[1] = 0x0f;
+                       sak = 0x01;
+               } break;                
                default: {
                        Dbprintf("Error: unkown tagtype (%d)",tagType);
                        return;
@@ -997,10 +967,11 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
        }
        
        // The second response contains the (mandatory) first 24 bits of the UID
-       uint8_t response2[5];
+       uint8_t response2[5] = {0x00};
 
        // Check if the uid uses the (optional) part
-       uint8_t response2a[5];
+       uint8_t response2a[5] = {0x00};
+       
        if (uid_2nd) {
                response2[0] = 0x88;
                num_to_bytes(uid_1st,3,response2+1);
@@ -1021,54 +992,68 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
        response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
 
        // Prepare the mandatory SAK (for 4 and 7 byte UID)
-       uint8_t response3[3];
+       uint8_t response3[3]  = {0x00};
        response3[0] = sak;
        ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
 
        // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
-       uint8_t response3a[3];
+       uint8_t response3a[3]  = {0x00};
        response3a[0] = sak & 0xFB;
        ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 
        uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
-       uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
+       uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS: 
+       // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present, 
+       // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
+       // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us)
+       // TC(1) = 0x02: CID supported, NAD not supported
        ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
 
-  #define TAG_RESPONSE_COUNT 7
-  tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
-    { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
-    { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
-    { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
-    { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
-    { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
-    { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
-    { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
-  };
-
-  // Allocate 512 bytes for the dynamic modulation, created when the reader querries for it
-  // Such a response is less time critical, so we can prepare them on the fly
-  #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
-  #define DYNAMIC_MODULATION_BUFFER_SIZE 512
-  uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
-  uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
-  tag_response_info_t dynamic_response_info = {
-    .response = dynamic_response_buffer,
-    .response_n = 0,
-    .modulation = dynamic_modulation_buffer,
-    .modulation_n = 0
-  };
-  
-  // Reset the offset pointer of the free buffer
-  reset_free_buffer();
+       #define TAG_RESPONSE_COUNT 7
+       tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
+               { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
+               { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
+               { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
+               { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
+               { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
+               { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
+               { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
+       };
+
+       // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
+       // Such a response is less time critical, so we can prepare them on the fly
+       #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
+       #define DYNAMIC_MODULATION_BUFFER_SIZE 512
+       uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
+       uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
+       tag_response_info_t dynamic_response_info = {
+               .response = dynamic_response_buffer,
+               .response_n = 0,
+               .modulation = dynamic_modulation_buffer,
+               .modulation_n = 0
+       };
   
-  // Prepare the responses of the anticollision phase
+       // We need to listen to the high-frequency, peak-detected path.
+       iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+       BigBuf_free_keep_EM();
+
+       // allocate buffers:
+       uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+       uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
+       free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
+
+       // clear trace
+       clear_trace();
+       set_tracing(TRUE);
+
+       // Prepare the responses of the anticollision phase
        // there will be not enough time to do this at the moment the reader sends it REQA
-  for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
-    prepare_allocated_tag_modulation(&responses[i]);
-  }
+       for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
+               prepare_allocated_tag_modulation(&responses[i]);
+       }
 
-       uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
-       int len;
+       int len = 0;
 
        // To control where we are in the protocol
        int order = 0;
@@ -1079,30 +1064,19 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
        int happened2 = 0;
        int cmdsRecvd = 0;
 
-       // We need to listen to the high-frequency, peak-detected path.
-       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-       FpgaSetupSsc();
-
        cmdsRecvd = 0;
-  tag_response_info_t* p_response;
+       tag_response_info_t* p_response;
 
        LED_A_ON();
        for(;;) {
-    // Clean receive command buffer
-    memset(receivedCmd, 0x44, RECV_CMD_SIZE);
-       
-               if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
+               // Clean receive command buffer
+               if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
                        DbpString("Button press");
                        break;
                }
-    
-               if (tracing) {
-                       LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE);
-               }
-    
-    p_response = NULL;
-    
-               // doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
+
+               p_response = NULL;
+               
                // Okay, look at the command now.
                lastorder = order;
                if(receivedCmd[0] == 0x26) { // Received a REQUEST
@@ -1111,87 +1085,104 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
                        p_response = &responses[0]; order = 6;
                } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {   // Received request for UID (cascade 1)
                        p_response = &responses[1]; order = 2;
-               } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
+               } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) {   // Received request for UID (cascade 2)
                        p_response = &responses[2]; order = 20;
                } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {   // Received a SELECT (cascade 1)
                        p_response = &responses[3]; order = 3;
                } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {   // Received a SELECT (cascade 2)
                        p_response = &responses[4]; order = 30;
                } else if(receivedCmd[0] == 0x30) {     // Received a (plain) READ
-                       EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
-                       Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
+                       EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
+                       // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
                        // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
-      p_response = NULL;
+                       p_response = NULL;
                } else if(receivedCmd[0] == 0x50) {     // Received a HALT
-//                     DbpString("Reader requested we HALT!:");
-      p_response = NULL;
+
+                       if (tracing) {
+                               LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                       }
+                       p_response = NULL;
                } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {   // Received an authentication request
                        p_response = &responses[5]; order = 7;
                } else if(receivedCmd[0] == 0xE0) {     // Received a RATS request
-                       p_response = &responses[6]; order = 70;
-               } else if (order == 7 && len ==8) { // Received authentication request
-      uint32_t nr = bytes_to_num(receivedCmd,4);
-      uint32_t ar = bytes_to_num(receivedCmd+4,4);
-      Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
-    } else {
-      // Check for ISO 14443A-4 compliant commands, look at left nibble
-      switch (receivedCmd[0]) {
-
-        case 0x0B:
-        case 0x0A: { // IBlock (command)
-          dynamic_response_info.response[0] = receivedCmd[0];
-          dynamic_response_info.response[1] = 0x00;
-          dynamic_response_info.response[2] = 0x90;
-          dynamic_response_info.response[3] = 0x00;
-          dynamic_response_info.response_n = 4;
-        } break;
-
-        case 0x1A:
-        case 0x1B: { // Chaining command
-          dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
-          dynamic_response_info.response_n = 2;
-        } break;
-
-        case 0xaa:
-        case 0xbb: {
-          dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
-          dynamic_response_info.response_n = 2;
-        } break;
-          
-        case 0xBA: { //
-          memcpy(dynamic_response_info.response,"\xAB\x00",2);
-          dynamic_response_info.response_n = 2;
-        } break;
-
-        case 0xCA:
-        case 0xC2: { // Readers sends deselect command
-          memcpy(dynamic_response_info.response,"\xCA\x00",2);
-          dynamic_response_info.response_n = 2;
-        } break;
-
-        default: {
-          // Never seen this command before
-          Dbprintf("Received unknown command (len=%d):",len);
-          Dbhexdump(len,receivedCmd,false);
-          // Do not respond
-          dynamic_response_info.response_n = 0;
-        } break;
-      }
+                       if (tagType == 1 || tagType == 2) {     // RATS not supported
+                               EmSend4bit(CARD_NACK_NA);
+                               p_response = NULL;
+                       } else {
+                               p_response = &responses[6]; order = 70;
+                       }
+               } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
+                       if (tracing) {
+                               LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                       }
+                       uint32_t nr = bytes_to_num(receivedCmd,4);
+                       uint32_t ar = bytes_to_num(receivedCmd+4,4);
+                       Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
+               } else {
+                       // Check for ISO 14443A-4 compliant commands, look at left nibble
+                       switch (receivedCmd[0]) {
+
+                               case 0x0B:
+                               case 0x0A: { // IBlock (command)
+                                 dynamic_response_info.response[0] = receivedCmd[0];
+                                 dynamic_response_info.response[1] = 0x00;
+                                 dynamic_response_info.response[2] = 0x90;
+                                 dynamic_response_info.response[3] = 0x00;
+                                 dynamic_response_info.response_n = 4;
+                               } break;
+
+                               case 0x1A:
+                               case 0x1B: { // Chaining command
+                                 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
+                                 dynamic_response_info.response_n = 2;
+                               } break;
+
+                               case 0xaa:
+                               case 0xbb: {
+                                 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
+                                 dynamic_response_info.response_n = 2;
+                               } break;
+                                 
+                               case 0xBA: { //
+                                 memcpy(dynamic_response_info.response,"\xAB\x00",2);
+                                 dynamic_response_info.response_n = 2;
+                               } break;
+
+                               case 0xCA:
+                               case 0xC2: { // Readers sends deselect command
+                                 memcpy(dynamic_response_info.response,"\xCA\x00",2);
+                                 dynamic_response_info.response_n = 2;
+                               } break;
+
+                               default: {
+                                       // Never seen this command before
+                                       if (tracing) {
+                                               LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       }
+                                       Dbprintf("Received unknown command (len=%d):",len);
+                                       Dbhexdump(len,receivedCmd,false);
+                                       // Do not respond
+                                       dynamic_response_info.response_n = 0;
+                               } break;
+                       }
       
-      if (dynamic_response_info.response_n > 0) {
-        // Copy the CID from the reader query
-        dynamic_response_info.response[1] = receivedCmd[1];
+                       if (dynamic_response_info.response_n > 0) {
+                               // Copy the CID from the reader query
+                               dynamic_response_info.response[1] = receivedCmd[1];
 
-        // Add CRC bytes, always used in ISO 14443A-4 compliant cards
-        AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
-        dynamic_response_info.response_n += 2;
+                               // Add CRC bytes, always used in ISO 14443A-4 compliant cards
+                               AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
+                               dynamic_response_info.response_n += 2;
         
-        if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
-          Dbprintf("Error preparing tag response");
-          break;
-        }
-        p_response = &dynamic_response_info;
-      }
+                               if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
+                                       Dbprintf("Error preparing tag response");
+                                       if (tracing) {
+                                               LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       }
+                                       break;
+                               }
+                               p_response = &dynamic_response_info;
+                       }
                }
 
                // Count number of wakeups received after a halt
@@ -1200,12 +1191,6 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
                // Count number of other messages after a halt
                if(order != 6 && lastorder == 5) { happened2++; }
 
-               // Look at last parity bit to determine timing of answer
-               if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) {
-                       // 1236, so correction bit needed
-                       //i = 0;
-               }
-
                if(cmdsRecvd > 999) {
                        DbpString("1000 commands later...");
                        break;
@@ -1213,19 +1198,32 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
                cmdsRecvd++;
 
                if (p_response != NULL) {
-      EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
-      if (tracing) {
-        LogTrace(p_response->response,p_response->response_n,0,SwapBits(GetParity(p_response->response,p_response->response_n),p_response->response_n),FALSE);
-        if(traceLen > TRACE_SIZE) {
-          DbpString("Trace full");
-//          break;
-        }
-      }
-    }
-  }
+                       EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
+                       // do the tracing for the previous reader request and this tag answer:
+                       uint8_t par[MAX_PARITY_SIZE];
+                       GetParity(p_response->response, p_response->response_n, par);
+       
+                       EmLogTrace(Uart.output, 
+                                               Uart.len, 
+                                               Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                                               Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                                               Uart.parity,
+                                               p_response->response, 
+                                               p_response->response_n,
+                                               LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+                                               (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+                                               par);
+               }
+               
+               if (!tracing) {
+                       Dbprintf("Trace Full. Simulation stopped.");
+                       break;
+               }
+       }
 
        Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
        LED_A_OFF();
+       BigBuf_free_keep_EM();
 }
 
 
@@ -1242,7 +1240,7 @@ void PrepareDelayedTransfer(uint16_t delay)
                for (uint16_t i = 0; i < delay; i++) {
                        bitmask |= (0x01 << i);
                }
-               ToSend[++ToSendMax] = 0x00;
+               ToSend[ToSendMax++] = 0x00;
                for (uint16_t i = 0; i < ToSendMax; i++) {
                        bits_to_shift = ToSend[i] & bitmask;
                        ToSend[i] = ToSend[i] >> delay;
@@ -1252,38 +1250,41 @@ void PrepareDelayedTransfer(uint16_t delay)
        }
 }
 
-//-----------------------------------------------------------------------------
+
+//-------------------------------------------------------------------------------------
 // Transmit the command (to the tag) that was placed in ToSend[].
 // Parameter timing:
-// if NULL: ignored
-// if == 0:    return time of transfer
+// if NULL: transfer at next possible time, taking into account
+//                     request guard time and frame delay time
+// if == 0:    transfer immediately and return time of transfer
 // if != 0: delay transfer until time specified
-//-----------------------------------------------------------------------------
-static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
+//-------------------------------------------------------------------------------------
+static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
 {
-       int c;
-
+       
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
 
+       uint32_t ThisTransferTime = 0;
 
        if (timing) {
                if(*timing == 0) {                                                                              // Measure time
-                       *timing = (GetCountMifare() + 8) & 0xfffffff8;
+                       *timing = (GetCountSspClk() + 8) & 0xfffffff8;
                } else {
                        PrepareDelayedTransfer(*timing & 0x00000007);           // Delay transfer (fine tuning - up to 7 MF clock ticks)
                }
-               if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
-               while(GetCountMifare() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
-       }
-
-       for(c = 0; c < 10;) {   // standard delay for each transfer (allow tag to be ready after last transmission?)
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       AT91C_BASE_SSC->SSC_THR = 0x00; 
-                       c++;
-               }
+               if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+               while(GetCountSspClk() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
+               LastTimeProxToAirStart = *timing;
+       } else {
+               ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
+               while(GetCountSspClk() < ThisTransferTime);
+               LastTimeProxToAirStart = ThisTransferTime;
        }
        
-       c = 0;
+       // clear TXRDY
+       AT91C_BASE_SSC->SSC_THR = SEC_Y;
+
+       uint16_t c = 0;
        for(;;) {
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
                        AT91C_BASE_SSC->SSC_THR = cmd[c];
@@ -1293,104 +1294,107 @@ static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
                        }
                }
        }
-
+       
+       NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
 }
 
+
 //-----------------------------------------------------------------------------
 // Prepare reader command (in bits, support short frames) to send to FPGA
 //-----------------------------------------------------------------------------
-void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
+void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
 {
-  int i, j;
-  int last;
-  uint8_t b;
-
-  ToSendReset();
-
-  // Start of Communication (Seq. Z)
-  ToSend[++ToSendMax] = SEC_Z;
-  last = 0;
-
-  size_t bytecount = nbytes(bits);
-  // Generate send structure for the data bits
-  for (i = 0; i < bytecount; i++) {
-    // Get the current byte to send
-    b = cmd[i];
-    size_t bitsleft = MIN((bits-(i*8)),8);
-
-    for (j = 0; j < bitsleft; j++) {
-      if (b & 1) {
-        // Sequence X
-         ToSend[++ToSendMax] = SEC_X;
-        last = 1;
-      } else {
-        if (last == 0) {
-          // Sequence Z
-               ToSend[++ToSendMax] = SEC_Z;
-        } else {
-          // Sequence Y
-               ToSend[++ToSendMax] = SEC_Y;
-          last = 0;
-        }
-      }
-      b >>= 1;
-    }
+       int i, j;
+       int last;
+       uint8_t b;
 
-    // Only transmit (last) parity bit if we transmitted a complete byte
-    if (j == 8) {
-      // Get the parity bit
-      if ((dwParity >> i) & 0x01) {
-        // Sequence X
-        ToSend[++ToSendMax] = SEC_X;
-        last = 1;
-      } else {
-        if (last == 0) {
-          // Sequence Z
-          ToSend[++ToSendMax] = SEC_Z;
-        } else {
-          // Sequence Y
-          ToSend[++ToSendMax] = SEC_Y;
-          last = 0;
-        }
-      }
-    }
-  }
+       ToSendReset();
 
-  // End of Communication
-  if (last == 0) {
-    // Sequence Z
-         ToSend[++ToSendMax] = SEC_Z;
-  } else {
-    // Sequence Y
-         ToSend[++ToSendMax] = SEC_Y;
-    last = 0;
-  }
-  // Sequence Y
-  ToSend[++ToSendMax] = SEC_Y;
+       // Start of Communication (Seq. Z)
+       ToSend[++ToSendMax] = SEC_Z;
+       LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+       last = 0;
+
+       size_t bytecount = nbytes(bits);
+       // Generate send structure for the data bits
+       for (i = 0; i < bytecount; i++) {
+               // Get the current byte to send
+               b = cmd[i];
+               size_t bitsleft = MIN((bits-(i*8)),8);
+
+               for (j = 0; j < bitsleft; j++) {
+                       if (b & 1) {
+                               // Sequence X
+                               ToSend[++ToSendMax] = SEC_X;
+                               LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+                               last = 1;
+                       } else {
+                               if (last == 0) {
+                               // Sequence Z
+                               ToSend[++ToSendMax] = SEC_Z;
+                               LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+                               } else {
+                                       // Sequence Y
+                                       ToSend[++ToSendMax] = SEC_Y;
+                                       last = 0;
+                               }
+                       }
+                       b >>= 1;
+               }
 
-  // Just to be sure!
-  ToSend[++ToSendMax] = SEC_Y;
-  ToSend[++ToSendMax] = SEC_Y;
-  ToSend[++ToSendMax] = SEC_Y;
+               // Only transmit parity bit if we transmitted a complete byte
+               if (j == 8 && parity != NULL) {
+                       // Get the parity bit
+                       if (parity[i>>3] & (0x80 >> (i&0x0007))) {
+                               // Sequence X
+                               ToSend[++ToSendMax] = SEC_X;
+                               LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+                               last = 1;
+                       } else {
+                               if (last == 0) {
+                                       // Sequence Z
+                                       ToSend[++ToSendMax] = SEC_Z;
+                                       LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+                               } else {
+                                       // Sequence Y
+                                       ToSend[++ToSendMax] = SEC_Y;
+                                       last = 0;
+                               }
+                       }
+               }
+       }
 
-  // Convert from last character reference to length
-  ToSendMax++;
+       // End of Communication: Logic 0 followed by Sequence Y
+       if (last == 0) {
+               // Sequence Z
+               ToSend[++ToSendMax] = SEC_Z;
+               LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+       } else {
+               // Sequence Y
+               ToSend[++ToSendMax] = SEC_Y;
+               last = 0;
+       }
+       ToSend[++ToSendMax] = SEC_Y;
+
+       // Convert to length of command:
+       ToSendMax++;
 }
 
 //-----------------------------------------------------------------------------
 // Prepare reader command to send to FPGA
 //-----------------------------------------------------------------------------
-void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
+void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
 {
-  CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
+  CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
 }
 
+
 //-----------------------------------------------------------------------------
 // Wait for commands from reader
 // Stop when button is pressed (return 1) or field was gone (return 2)
 // Or return 0 when command is captured
 //-----------------------------------------------------------------------------
-static int EmGetCmd(uint8_t *received, int *len, int maxLen)
+static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
 {
        *len = 0;
 
@@ -1407,18 +1411,19 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen)
        // Set ADC to read field strength
        AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
        AT91C_BASE_ADC->ADC_MR =
-                               ADC_MODE_PRESCALE(32) |
-                               ADC_MODE_STARTUP_TIME(16) |
-                               ADC_MODE_SAMPLE_HOLD_TIME(8);
+                               ADC_MODE_PRESCALE(63) |
+                               ADC_MODE_STARTUP_TIME(1) |
+                               ADC_MODE_SAMPLE_HOLD_TIME(15);
        AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
        // start ADC
        AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
        
        // Now run a 'software UART' on the stream of incoming samples.
-       Uart.output = received;
-       Uart.byteCntMax = maxLen;
-       Uart.state = STATE_UNSYNCD;
+       UartInit(received, parity);
 
+       // Clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+       
        for(;;) {
                WDT_HIT();
 
@@ -1430,7 +1435,7 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen)
                        analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
                        AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
                        if (analogCnt >= 32) {
-                               if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
+                               if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
                                        vtime = GetTickCount();
                                        if (!timer) timer = vtime;
                                        // 50ms no field --> card to idle state
@@ -1440,99 +1445,159 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen)
                                analogCnt = 0;
                                analogAVG = 0;
                        }
-               }
-               // transmit none
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       AT91C_BASE_SSC->SSC_THR = 0x00;
-               }
-               // receive and test the miller decoding
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       if(MillerDecoding((b & 0xf0) >> 4)) {
-                               *len = Uart.byteCnt;
-                               if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
-                               return 0;
-                       }
-                       if(MillerDecoding(b & 0x0f)) {
-                               *len = Uart.byteCnt;
-                               if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
+               }
+
+               // receive and test the miller decoding
+        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+            b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       if(MillerDecoding(b, 0)) {
+                               *len = Uart.len;
                                return 0;
                        }
-               }
+        }
+
        }
 }
 
-static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded)
-{
-       int i, u = 0;
-       uint8_t b = 0;
 
+static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
+{
+       uint8_t b;
+       uint16_t i = 0;
+       uint32_t ThisTransferTime;
+       
        // Modulate Manchester
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
-       AT91C_BASE_SSC->SSC_THR = 0x00;
-       FpgaSetupSsc();
-       
-       // include correction bit
-       i = 1;
-       if((Uart.parityBits & 0x01) || correctionNeeded) {
+
+       // include correction bit if necessary
+       if (Uart.parityBits & 0x01) {
+               correctionNeeded = TRUE;
+       }
+       if(correctionNeeded) {
                // 1236, so correction bit needed
                i = 0;
+       } else {
+               i = 1;
        }
+
+       // clear receiving shift register and holding register
+       while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+       b = AT91C_BASE_SSC->SSC_RHR; (void) b;
+       while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+       b = AT91C_BASE_SSC->SSC_RHR; (void) b;
        
+       // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
+       for (uint16_t j = 0; j < 5; j++) {      // allow timeout - better late than never
+               while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+               if (AT91C_BASE_SSC->SSC_RHR) break;
+       }
+
+       while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
+
+       // Clear TXRDY:
+       AT91C_BASE_SSC->SSC_THR = SEC_F;
+
        // send cycle
-       for(;;) {
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       (void)b;
-               }
+       for(; i < respLen; ) {
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       if(i > respLen) {
-                               b = 0xff; // was 0x00
-                               u++;
-                       } else {
-                               b = resp[i];
-                               i++;
-                       }
-                       AT91C_BASE_SSC->SSC_THR = b;
-
-                       if(u > 4) break;
+                       AT91C_BASE_SSC->SSC_THR = resp[i++];
+                       FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
                }
+       
                if(BUTTON_PRESS()) {
                        break;
                }
        }
 
+       // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
+       uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
+       for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
+               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       AT91C_BASE_SSC->SSC_THR = SEC_F;
+                       FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       i++;
+               }
+       }
+
+       LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
+
        return 0;
 }
 
-int EmSend4bitEx(uint8_t resp, int correctionNeeded){
-  Code4bitAnswerAsTag(resp);
+int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
+       Code4bitAnswerAsTag(resp);
        int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
-  if (tracing) LogTrace(&resp, 1, GetDeltaCountUS(), GetParity(&resp, 1), FALSE);
+       // do the tracing for the previous reader request and this tag answer:
+       uint8_t par[1];
+       GetParity(&resp, 1, par);
+       EmLogTrace(Uart.output, 
+                               Uart.len, 
+                               Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                               Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                               Uart.parity,
+                               &resp, 
+                               1, 
+                               LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+                               (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+                               par);
        return res;
 }
 
 int EmSend4bit(uint8_t resp){
-       return EmSend4bitEx(resp, 0);
+       return EmSend4bitEx(resp, false);
 }
 
-int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par){
-  CodeIso14443aAsTagPar(resp, respLen, par);
+int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
+       CodeIso14443aAsTagPar(resp, respLen, par);
        int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
-  if (tracing) LogTrace(resp, respLen, GetDeltaCountUS(), par, FALSE);
+       // do the tracing for the previous reader request and this tag answer:
+       EmLogTrace(Uart.output, 
+                               Uart.len, 
+                               Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                               Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+                               Uart.parity,
+                               resp, 
+                               respLen, 
+                               LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+                               (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+                               par);
        return res;
 }
 
-int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded){
-       return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
+int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
+       uint8_t par[MAX_PARITY_SIZE];
+       GetParity(resp, respLen, par);
+       return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
+}
+
+int EmSendCmd(uint8_t *resp, uint16_t respLen){
+       uint8_t par[MAX_PARITY_SIZE];
+       GetParity(resp, respLen, par);
+       return EmSendCmdExPar(resp, respLen, false, par);
 }
 
-int EmSendCmd(uint8_t *resp, int respLen){
-       return EmSendCmdExPar(resp, respLen, 0, GetParity(resp, respLen));
+int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
+       return EmSendCmdExPar(resp, respLen, false, par);
 }
 
-int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
-       return EmSendCmdExPar(resp, respLen, 0, par);
+bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
+                                uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
+{
+       if (tracing) {
+               // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
+               // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
+               // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
+               uint16_t reader_modlen = reader_EndTime - reader_StartTime;
+               uint16_t approx_fdt = tag_StartTime - reader_EndTime;
+               uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
+               reader_EndTime = tag_StartTime - exact_fdt;
+               reader_StartTime = reader_EndTime - reader_modlen;
+               if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
+                       return FALSE;
+               } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
+       } else {
+               return TRUE;
+       }
 }
 
 //-----------------------------------------------------------------------------
@@ -1540,9 +1605,9 @@ int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
 //  If a response is captured return TRUE
 //  If it takes too long return FALSE
 //-----------------------------------------------------------------------------
-static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen, int *samples)
+static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
 {
-       int c;
+       uint32_t c;
        
        // Set FPGA mode to "reader listen mode", no modulation (listen
        // only, since we are receiving, not transmitting).
@@ -1551,245 +1616,261 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset,
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
        
        // Now get the answer from the card
-       Demod.output = receivedResponse;
-       Demod.len = 0;
-       Demod.state = DEMOD_UNSYNCD;
+       DemodInit(receivedResponse, receivedResponsePar);
 
-       uint8_t b;
+       // clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 
        c = 0;
        for(;;) {
                WDT_HIT();
 
-               // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       // AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
-                       // if (elapsed) (*elapsed)++;
-               // }
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       if(c < iso14a_timeout) { c++; } else { return FALSE; }
                        b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       if(ManchesterDecoding(b, offset)) {
-                               *samples = Demod.samples;
+                       if(ManchesterDecoding(b, offset, 0)) {
+                               NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
                                return TRUE;
+                       } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
+                               return FALSE; 
                        }
                }
        }
 }
 
-void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
-{
 
-  CodeIso14443aBitsAsReaderPar(frame,bits,par);
+void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
+{
+       CodeIso14443aBitsAsReaderPar(frame, bits, par);
   
-  // Send command to tag
-  TransmitFor14443a(ToSend, ToSendMax, timing);
-  if(trigger)
-       LED_A_ON();
+       // Send command to tag
+       TransmitFor14443a(ToSend, ToSendMax, timing);
+       if(trigger)
+               LED_A_ON();
   
-  // Log reader command in trace buffer
-  if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
+       // Log reader command in trace buffer
+       if (tracing) {
+               LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
+       }
 }
 
-void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
+
+void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
 {
-  ReaderTransmitBitsPar(frame,len*8,par, timing);
+  ReaderTransmitBitsPar(frame, len*8, par, timing);
 }
 
-void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
+
+void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
 {
   // Generate parity and redirect
-  ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
+  uint8_t par[MAX_PARITY_SIZE];
+  GetParity(frame, len/8, par);
+  ReaderTransmitBitsPar(frame, len, par, timing);
 }
 
-void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
+
+void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
 {
   // Generate parity and redirect
-  ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
+  uint8_t par[MAX_PARITY_SIZE];
+  GetParity(frame, len, par);
+  ReaderTransmitBitsPar(frame, len*8, par, timing);
 }
 
-int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
+int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
 {
-       int samples = 0;
-       if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160,&samples)) return FALSE;
-       if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
-       if(samples == 0) return FALSE;
+       if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
+       if (tracing) {
+               LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+       }
        return Demod.len;
 }
 
-int ReaderReceive(uint8_t* receivedAnswer)
+int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
 {
-       return ReaderReceiveOffset(receivedAnswer, 0);
-}
-
-int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
-{
-       int samples = 0;
-       if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160,&samples)) return FALSE;
-       if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
-       *parptr = Demod.parityBits;
-       if(samples == 0) return FALSE;
+       if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
+       if (tracing) {
+               LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+       }
        return Demod.len;
 }
 
 /* performs iso14443a anticollision procedure
  * fills the uid pointer unless NULL
  * fills resp_data unless NULL */
-int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
-  uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
-  uint8_t sel_all[]    = { 0x93,0x20 };
-  uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-  uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
-  uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);  // was 3560 - tied to other size changes
-  byte_t uid_resp[4];
-  size_t uid_resp_len;
-
-  uint8_t sak = 0x04; // cascade uid
-  int cascade_level = 0;
-  int len;
-        
-  // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) {
+       uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
+       uint8_t sel_all[]    = { 0x93,0x20 };
+       uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+       uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
+       uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
+       uint8_t resp_par[MAX_PARITY_SIZE];
+       byte_t uid_resp[4];
+       size_t uid_resp_len;
+
+       uint8_t sak = 0x04; // cascade uid
+       int cascade_level = 0;
+       int len;
+
+       // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
     ReaderTransmitBitsPar(wupa,7,0, NULL);
-  // Receive the ATQA
-  if(!ReaderReceive(resp)) return 0;
-  // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
-
-  if(p_hi14a_card) {
-    memcpy(p_hi14a_card->atqa, resp, 2);
-    p_hi14a_card->uidlen = 0;
-    memset(p_hi14a_card->uid,0,10);
-  }
+       
+       // Receive the ATQA
+       if(!ReaderReceive(resp, resp_par)) return 0;
 
-  // clear uid
-  if (uid_ptr) {
-    memset(uid_ptr,0,10);
-  }
+       if(p_hi14a_card) {
+               memcpy(p_hi14a_card->atqa, resp, 2);
+               p_hi14a_card->uidlen = 0;
+               memset(p_hi14a_card->uid,0,10);
+       }
+
+       // clear uid
+       if (uid_ptr) {
+               memset(uid_ptr,0,10);
+       }
 
-  // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
-  // which case we need to make a cascade 2 request and select - this is a long UID
-  // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
-  for(; sak & 0x04; cascade_level++) {
-    // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
-    sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
-
-    // SELECT_ALL
-    ReaderTransmit(sel_all,sizeof(sel_all), NULL);
-    if (!ReaderReceive(resp)) return 0;
-
-       if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
-               memset(uid_resp, 0, 4);
-               uint16_t uid_resp_bits = 0;
-               uint16_t collision_answer_offset = 0;
-               // anti-collision-loop:
-               while (Demod.collisionPos) {
-                       Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
-                       for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
-                               uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
-                               uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
+       // check for proprietary anticollision:
+       if ((resp[0] & 0x1F) == 0) {
+               return 3;
+       }
+       
+       // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
+       // which case we need to make a cascade 2 request and select - this is a long UID
+       // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
+       for(; sak & 0x04; cascade_level++) {
+               // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
+               sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
+
+               // SELECT_ALL
+               ReaderTransmit(sel_all, sizeof(sel_all), NULL);
+               if (!ReaderReceive(resp, resp_par)) return 0;
+
+               if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
+                       memset(uid_resp, 0, 4);
+                       uint16_t uid_resp_bits = 0;
+                       uint16_t collision_answer_offset = 0;
+                       // anti-collision-loop:
+                       while (Demod.collisionPos) {
+                               Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
+                               for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
+                                       uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
+                                       uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
+                               }
+                               uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
+                               uid_resp_bits++;
+                               // construct anticollosion command:
+                               sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
+                               for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
+                                       sel_uid[2+i] = uid_resp[i];
+                               }
+                               collision_answer_offset = uid_resp_bits%8;
+                               ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
+                               if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
                        }
-                       uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
-                       uid_resp_bits++;
-                       // construct anticollosion command:
-                       sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
-                       for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
-                               sel_uid[2+i] = uid_resp[i];
+                       // finally, add the last bits and BCC of the UID
+                       for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
+                               uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
+                               uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
                        }
-                       collision_answer_offset = uid_resp_bits%8;
-                       ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
-                       if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
+
+               } else {                // no collision, use the response to SELECT_ALL as current uid
+                       memcpy(uid_resp, resp, 4);
                }
-               // finally, add the last bits and BCC of the UID
-               for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
-                       uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
-                       uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
+               uid_resp_len = 4;
+
+               // calculate crypto UID. Always use last 4 Bytes.
+               if(cuid_ptr) {
+                       *cuid_ptr = bytes_to_num(uid_resp, 4);
                }
 
-       } else {                // no collision, use the response to SELECT_ALL as current uid
-               memcpy(uid_resp,resp,4);
-       }
-       uid_resp_len = 4;
-    //    Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
+               // Construct SELECT UID command
+               sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
+               memcpy(sel_uid+2, uid_resp, 4);                                                                         // the UID
+               sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
+               AppendCrc14443a(sel_uid, 7);                                                                            // calculate and add CRC
+               ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
+
+               // Receive the SAK
+               if (!ReaderReceive(resp, resp_par)) return 0;
+               sak = resp[0];
+
+    // Test if more parts of the uid are coming
+               if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
+                       // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
+                       // http://www.nxp.com/documents/application_note/AN10927.pdf
+                       uid_resp[0] = uid_resp[1];
+                       uid_resp[1] = uid_resp[2];
+                       uid_resp[2] = uid_resp[3]; 
+
+                       uid_resp_len = 3;
+               }
 
-    // calculate crypto UID. Always use last 4 Bytes.
-    if(cuid_ptr) {
-        *cuid_ptr = bytes_to_num(uid_resp, 4);
-    }
+               if(uid_ptr) {
+                       memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
+               }
 
-    // Construct SELECT UID command
-       sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
-    memcpy(sel_uid+2,uid_resp,4);                                                                              // the UID
-       sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
-    AppendCrc14443a(sel_uid,7);                                                                                        // calculate and add CRC
-    ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
-
-    // Receive the SAK
-    if (!ReaderReceive(resp)) return 0;
-    sak = resp[0];
-
-    // Test if more parts of the uid are comming
-    if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
-      // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
-      // http://www.nxp.com/documents/application_note/AN10927.pdf
-      memcpy(uid_resp, uid_resp + 1, 3);
-      uid_resp_len = 3;
-    }
+               if(p_hi14a_card) {
+                       memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
+                       p_hi14a_card->uidlen += uid_resp_len;
+               }
+       }
 
-    if(uid_ptr) {
-      memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
-    }
+       if(p_hi14a_card) {
+               p_hi14a_card->sak = sak;
+               p_hi14a_card->ats_len = 0;
+       }
 
-    if(p_hi14a_card) {
-      memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
-      p_hi14a_card->uidlen += uid_resp_len;
-    }
-  }
+       // non iso14443a compliant tag
+       if( (sak & 0x20) == 0) return 2; 
 
-  if(p_hi14a_card) {
-    p_hi14a_card->sak = sak;
-    p_hi14a_card->ats_len = 0;
-  }
+       // Request for answer to select
+       AppendCrc14443a(rats, 2);
+       ReaderTransmit(rats, sizeof(rats), NULL);
 
-  if( (sak & 0x20) == 0) {
-    return 2; // non iso14443a compliant tag
-  }
+       if (!(len = ReaderReceive(resp, resp_par))) return 0;
 
-  // Request for answer to select
-  AppendCrc14443a(rats, 2);
-  ReaderTransmit(rats, sizeof(rats), NULL);
+       
+       if(p_hi14a_card) {
+               memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
+               p_hi14a_card->ats_len = len;
+       }
 
-  if (!(len = ReaderReceive(resp))) return 0;
+       // reset the PCB block number
+       iso14_pcb_blocknum = 0;
 
-  if(p_hi14a_card) {
-    memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
-    p_hi14a_card->ats_len = len;
-  }
+       // set default timeout based on ATS
+       iso14a_set_ATS_timeout(resp);
 
-  // reset the PCB block number
-  iso14_pcb_blocknum = 0;
-  return 1;
+       return 1;       
 }
 
-void iso14443a_setup() {
+void iso14443a_setup(uint8_t fpga_minor_mode) {
+       FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
        // Set up the synchronous serial port
        FpgaSetupSsc();
-       // Start from off (no field generated)
-       // Signal field is off with the appropriate LED
-//     LED_D_OFF();
-//     FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       // SpinDelay(50);
-
+       // connect Demodulated Signal to ADC:
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-       // Now give it time to spin up.
        // Signal field is on with the appropriate LED
-       LED_D_ON();
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-       SpinDelay(7); // iso14443-3 specifies 5ms max.
+       if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
+               || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
+               LED_D_ON();
+       } else {
+               LED_D_OFF();
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
 
-       Demod.state = DEMOD_UNSYNCD;
-       iso14a_timeout = 2048; //default
+       // Start the timer
+       StartCountSspClk();
+       
+       DemodReset();
+       UartReset();
+       NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
+       iso14a_set_timeout(1050); // 10ms default
 }
 
-int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
+int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
+       uint8_t parity[MAX_PARITY_SIZE];
        uint8_t real_cmd[cmd_len+4];
        real_cmd[0] = 0x0a; //I-Block
        // put block number into the PCB
@@ -1799,8 +1880,8 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
        AppendCrc14443a(real_cmd,cmd_len+2);
  
        ReaderTransmit(real_cmd, cmd_len+4, NULL);
-       size_t len = ReaderReceive(data);
-       uint8_t * data_bytes = (uint8_t *) data;
+       size_t len = ReaderReceive(data, parity);
+       uint8_t *data_bytes = (uint8_t *) data;
        if (!len)
                return 0; //DATA LINK ERROR
        // if we received an I- or R(ACK)-Block with a block number equal to the
@@ -1820,27 +1901,29 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
 // Read an ISO 14443a tag. Send out commands and store answers.
 //
 //-----------------------------------------------------------------------------
-void ReaderIso14443a(UsbCommand * c)
+void ReaderIso14443a(UsbCommand *c)
 {
        iso14a_command_t param = c->arg[0];
-       uint8_t * cmd = c->d.asBytes;
-       size_t len = c->arg[1];
-       size_t lenbits = c->arg[2];
+       uint8_t *cmd = c->d.asBytes;
+       size_t len = c->arg[1] & 0xffff;
+       size_t lenbits = c->arg[1] >> 16;
+       uint32_t timeout = c->arg[2];
        uint32_t arg0 = 0;
        byte_t buf[USB_CMD_DATA_SIZE];
+       uint8_t par[MAX_PARITY_SIZE];
   
        if(param & ISO14A_CONNECT) {
-               iso14a_clear_trace();
+               clear_trace();
        }
 
-       iso14a_set_tracing(true);
+       set_tracing(TRUE);
 
        if(param & ISO14A_REQUEST_TRIGGER) {
-               iso14a_set_trigger(1);
+               iso14a_set_trigger(TRUE);
        }
 
        if(param & ISO14A_CONNECT) {
-               iso14443a_setup();
+               iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
                if(!(param & ISO14A_NO_SELECT)) {
                        iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
                        arg0 = iso14443a_select_card(NULL,card,NULL);
@@ -1849,11 +1932,7 @@ void ReaderIso14443a(UsbCommand * c)
        }
 
        if(param & ISO14A_SET_TIMEOUT) {
-               iso14a_timeout = c->arg[2];
-       }
-
-       if(param & ISO14A_SET_TIMEOUT) {
-               iso14a_timeout = c->arg[2];
+               iso14a_set_timeout(timeout);
        }
 
        if(param & ISO14A_APDU) {
@@ -1863,20 +1942,45 @@ void ReaderIso14443a(UsbCommand * c)
 
        if(param & ISO14A_RAW) {
                if(param & ISO14A_APPEND_CRC) {
-                       AppendCrc14443a(cmd,len);
+                       if(param & ISO14A_TOPAZMODE) {
+                               AppendCrc14443b(cmd,len);
+                       } else {
+                               AppendCrc14443a(cmd,len);
+                       }
                        len += 2;
+                       if (lenbits) lenbits += 16;
                }
-               if(lenbits>0) {
-                       ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
-               } else {
-                       ReaderTransmit(cmd,len, NULL);
+               if(lenbits>0) {                         // want to send a specific number of bits (e.g. short commands)
+                       if(param & ISO14A_TOPAZMODE) {
+                               int bits_to_send = lenbits;
+                               uint16_t i = 0;
+                               ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL);             // first byte is always short (7bits) and no parity
+                               bits_to_send -= 7;
+                               while (bits_to_send > 0) {
+                                       ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL);     // following bytes are 8 bit and no parity
+                                       bits_to_send -= 8;
+                               }
+                       } else {
+                               GetParity(cmd, lenbits/8, par);
+                               ReaderTransmitBitsPar(cmd, lenbits, par, NULL);                                                 // bytes are 8 bit with odd parity
+                       }
+               } else {                                        // want to send complete bytes only
+                       if(param & ISO14A_TOPAZMODE) {
+                               uint16_t i = 0;
+                               ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL);                                                // first byte: 7 bits, no paritiy
+                               while (i < len) {
+                                       ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL);                                        // following bytes: 8 bits, no paritiy
+                               }
+                       } else {
+                               ReaderTransmit(cmd,len, NULL);                                                                                  // 8 bits, odd parity
+                       }
                }
-               arg0 = ReaderReceive(buf);
+               arg0 = ReaderReceive(buf, par);
                cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
        }
 
        if(param & ISO14A_REQUEST_TRIGGER) {
-               iso14a_set_trigger(0);
+               iso14a_set_trigger(FALSE);
        }
 
        if(param & ISO14A_NO_DISCONNECT) {
@@ -1905,7 +2009,7 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
                nttmp1 = prng_successor(nttmp1, 1);
                if (nttmp1 == nt2) return i;
                nttmp2 = prng_successor(nttmp2, 1);
-                       if (nttmp2 == nt1) return -i;
+               if (nttmp2 == nt1) return -i;
                }
        
        return(-99999); // either nt1 or nt2 are invalid nonces
@@ -1925,49 +2029,53 @@ void ReaderMifare(bool first_try)
        uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
        static uint8_t mf_nr_ar3;
 
-       uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
-       iso14a_clear_trace();
-       tracing = false;
+       uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
+       uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
+
+       if (first_try) { 
+               iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+       }
+       
+       // free eventually allocated BigBuf memory. We want all for tracing.
+       BigBuf_free();
+       
+       clear_trace();
+       set_tracing(TRUE);
 
        byte_t nt_diff = 0;
-       byte_t par = 0;
-       //byte_t par_mask = 0xff;
+       uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
        static byte_t par_low = 0;
        bool led_on = TRUE;
-       uint8_t uid[10];
+       uint8_t uid[10]  ={0};
        uint32_t cuid;
 
-       uint32_t nt, previous_nt;
+       uint32_t nt = 0;
+       uint32_t previous_nt = 0;
        static uint32_t nt_attacked = 0;
-       byte_t par_list[8] = {0,0,0,0,0,0,0,0};
-       byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
+       byte_t par_list[8] = {0x00};
+       byte_t ks_list[8] = {0x00};
 
+       #define PRNG_SEQUENCE_LENGTH  (1 << 16);
        static uint32_t sync_time;
-       static uint32_t sync_cycles;
+       static int32_t sync_cycles;
        int catch_up_cycles = 0;
        int last_catch_up = 0;
+       uint16_t elapsed_prng_sequences;
        uint16_t consecutive_resyncs = 0;
        int isOK = 0;
 
-
-
        if (first_try) { 
-               StartCountMifare();
                mf_nr_ar3 = 0;
-               iso14443a_setup();
-               while((GetCountMifare() & 0xffff0000) != 0x10000);              // wait for counter to reset and "warm up" 
-               sync_time = GetCountMifare() & 0xfffffff8;
-               sync_cycles = 65536;                                                                    // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+               sync_time = GetCountSspClk() & 0xfffffff8;
+               sync_cycles = PRNG_SEQUENCE_LENGTH;                                                     // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the tag nonces).
                nt_attacked = 0;
-               nt = 0;
-               par = 0;
+               par[0] = 0;
        }
        else {
                // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
-               // nt_attacked = prng_successor(nt_attacked, 1);
                mf_nr_ar3++;
                mf_nr_ar[3] = mf_nr_ar3;
-               par = par_low;
+               par[0] = par_low;
        }
 
        LED_A_ON();
@@ -1975,38 +2083,86 @@ void ReaderMifare(bool first_try)
        LED_C_OFF();
        
 
+       #define MAX_UNEXPECTED_RANDOM   4               // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
+       #define MAX_SYNC_TRIES                  32
+       #define NUM_DEBUG_INFOS                 8               // per strategy
+       #define MAX_STRATEGY                    3
+       uint16_t unexpected_random = 0;
+       uint16_t sync_tries = 0;
+       int16_t debug_info_nr = -1;
+       uint16_t strategy = 0;
+       int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS];
+       uint32_t select_time;
+       uint32_t halt_time;
+       
        for(uint16_t i = 0; TRUE; i++) {
                
+               LED_C_ON();
                WDT_HIT();
 
                // Test if the action was cancelled
                if(BUTTON_PRESS()) {
+                       isOK = -1;
                        break;
                }
                
-               LED_C_ON();
+               if (strategy == 2) {
+                       // test with additional hlt command
+                       halt_time = 0;
+                       int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
+                       if (len && MF_DBGLEVEL >= 3) {
+                               Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len);
+                       }
+               }
 
+               if (strategy == 3) {
+                       // test with FPGA power off/on
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                       SpinDelay(200);
+                       iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+                       SpinDelay(100);
+               }
+               
                if(!iso14443a_select_card(uid, NULL, &cuid)) {
                        if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Can't select card");
                        continue;
                }
+               select_time = GetCountSspClk();
 
-               //keep the card active
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+               elapsed_prng_sequences = 1;
+               if (debug_info_nr == -1) {
+                       sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+                       catch_up_cycles = 0;
 
-               sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
-               catch_up_cycles = 0;
-
-               // if we missed the sync time already, advance to the next nonce repeat
-               while(GetCountMifare() > sync_time) {
-                       sync_time = (sync_time & 0xfffffff8) + sync_cycles;
-               }
+                       // if we missed the sync time already, advance to the next nonce repeat
+                       while(GetCountSspClk() > sync_time) {
+                               elapsed_prng_sequences++;
+                               sync_time = (sync_time & 0xfffffff8) + sync_cycles;
+                       }
 
-               // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) 
-               ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+                       // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) 
+                       ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+               } else {
+                       // collect some information on tag nonces for debugging:
+                       #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH
+                       if (strategy == 0) {
+                               // nonce distances at fixed time after card select:
+                               sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES;
+                       } else if (strategy == 1) {
+                               // nonce distances at fixed time between authentications:
+                               sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES;
+                       } else if (strategy == 2) {
+                               // nonce distances at fixed time after halt:
+                               sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES;
+                       } else {
+                               // nonce_distances at fixed time after power on
+                               sync_time = DEBUG_FIXED_SYNC_CYCLES;
+                       }
+                       ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+               }                       
 
                // Receive the (4 Byte) "random" nonce
-               if (!ReaderReceive(receivedAnswer)) {
+               if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
                        if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Couldn't receive tag nonce");
                        continue;
                  }
@@ -2021,13 +2177,37 @@ void ReaderMifare(bool first_try)
                        int nt_distance = dist_nt(previous_nt, nt);
                        if (nt_distance == 0) {
                                nt_attacked = nt;
-                       }
-                       else {
-                               if (nt_distance == -99999) { // invalid nonce received, try again
-                                       continue;
+                       } else {
+                               if (nt_distance == -99999) { // invalid nonce received
+                                       unexpected_random++;
+                                       if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
+                                               isOK = -3;              // Card has an unpredictable PRNG. Give up      
+                                               break;
+                                       } else {
+                                               continue;               // continue trying...
+                                       }
+                               }
+                               if (++sync_tries > MAX_SYNC_TRIES) {
+                                       if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
+                                               isOK = -4;                      // Card's PRNG runs at an unexpected frequency or resets unexpectedly
+                                               break;
+                                       } else {                                // continue for a while, just to collect some debug info
+                                               debug_info[strategy][debug_info_nr] = nt_distance;
+                                               debug_info_nr++;
+                                               if (debug_info_nr == NUM_DEBUG_INFOS) {
+                                                       strategy++;
+                                                       debug_info_nr = 0;
+                                               }
+                                               continue;
+                                       }
+                               }
+                               sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences);
+                               if (sync_cycles <= 0) {
+                                       sync_cycles += PRNG_SEQUENCE_LENGTH;
+                               }
+                               if (MF_DBGLEVEL >= 3) {
+                                       Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles);
                                }
-                               sync_cycles = (sync_cycles - nt_distance);
-                               if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
                                continue;
                        }
                }
@@ -2038,6 +2218,7 @@ void ReaderMifare(bool first_try)
                                catch_up_cycles = 0;
                                continue;
                        }
+                       catch_up_cycles /= elapsed_prng_sequences;
                        if (catch_up_cycles == last_catch_up) {
                                consecutive_resyncs++;
                        }
@@ -2051,6 +2232,9 @@ void ReaderMifare(bool first_try)
                        else {  
                                sync_cycles = sync_cycles + catch_up_cycles;
                                if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
+                               last_catch_up = 0;
+                               catch_up_cycles = 0;
+                               consecutive_resyncs = 0;
                        }
                        continue;
                }
@@ -2058,19 +2242,17 @@ void ReaderMifare(bool first_try)
                consecutive_resyncs = 0;
                
                // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
-               if (ReaderReceive(receivedAnswer))
-               {
+               if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
                        catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
        
-                       if (nt_diff == 0)
-                       {
-                               par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
+                       if (nt_diff == 0) {
+                               par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
                        }
 
                        led_on = !led_on;
                        if(led_on) LED_B_ON(); else LED_B_OFF();
 
-                       par_list[nt_diff] = par;
+                       par_list[nt_diff] = SwapBits(par[0], 8);
                        ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
 
                        // Test if the information is complete
@@ -2081,22 +2263,33 @@ void ReaderMifare(bool first_try)
 
                        nt_diff = (nt_diff + 1) & 0x07;
                        mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
-                       par = par_low;
+                       par[0] = par_low;
                } else {
                        if (nt_diff == 0 && first_try)
                        {
-                               par++;
+                               par[0]++;
+                               if (par[0] == 0x00) {           // tried all 256 possible parities without success. Card doesn't send NACK.
+                                       isOK = -2;
+                                       break;
+                               }
                        } else {
-                               par = (((par >> 3) + 1) << 3) | par_low;
+                               par[0] = ((par[0] & 0x1F) + 1) | par_low;
                        }
                }
        }
 
-       LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE);
-       LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE);
-       LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE);
 
        mf_nr_ar[3] &= 0x1F;
+
+       if (isOK == -4) {
+               if (MF_DBGLEVEL >= 3) {
+                       for (uint16_t i = 0; i <= MAX_STRATEGY; i++) {
+                               for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) {
+                                       Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]);
+                               }
+                       }
+               }
+       }
        
        byte_t buf[28];
        memcpy(buf + 0,  uid, 4);
@@ -2105,12 +2298,13 @@ void ReaderMifare(bool first_try)
        memcpy(buf + 16, ks_list, 8);
        memcpy(buf + 24, mf_nr_ar, 4);
                
-       cmd_send(CMD_ACK,isOK,0,0,buf,28);
+       cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
 
        // Thats it...
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LEDsoff();
-       tracing = TRUE;
+
+       set_tracing(FALSE);
 }
 
 /**
@@ -2131,8 +2325,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
        int res;
        uint32_t selTimer = 0;
        uint32_t authTimer = 0;
-       uint32_t par = 0;
-       int len = 0;
+       uint16_t len = 0;
        uint8_t cardWRBL = 0;
        uint8_t cardAUTHSC = 0;
        uint8_t cardAUTHKEY = 0xff;  // no authentication
@@ -2146,8 +2339,10 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
        struct Crypto1State *pcs;
        pcs = &mpcs;
        uint32_t numReads = 0;//Counts numer of times reader read a block
-       uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
-       uint8_t *response = eml_get_bigbufptr_sendbuf();
+       uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
+       uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
+       uint8_t response[MAX_MIFARE_FRAME_SIZE];
+       uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
        
        uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
        uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
@@ -2157,39 +2352,31 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
        uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
        uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
-
+               
        //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
        // This can be used in a reader-only attack.
        // (it can also be retrieved via 'hf 14a list', but hey...
        uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
        uint8_t ar_nr_collected = 0;
 
-       // clear trace
-       iso14a_clear_trace();
-
-       tracing = true;
-
-  // Authenticate response - nonce
+       // Authenticate response - nonce
        uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
-
+       
        //-- Determine the UID
        // Can be set from emulator memory, incoming data
        // and can be 7 or 4 bytes long
-       if(flags & FLAG_4B_UID_IN_DATA)
+       if (flags & FLAG_4B_UID_IN_DATA)
        {
                // 4B uid comes from data-portion of packet
                memcpy(rUIDBCC1,datain,4);
                rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
 
-       }else if(flags & FLAG_7B_UID_IN_DATA)
-       {
+       } else if (flags & FLAG_7B_UID_IN_DATA) {
                // 7B uid comes from data-portion of packet
                memcpy(&rUIDBCC1[1],datain,3);
                memcpy(rUIDBCC2, datain+3, 4);
                _7BUID = true;
-       }
-       else
-       {
+       } else {
                // get UID from emul memory
                emlGetMemBt(receivedCmd, 7, 1);
                _7BUID = !(receivedCmd[0] == 0x00);
@@ -2200,48 +2387,48 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                        emlGetMemBt(rUIDBCC2, 3, 4);
                }
        }
+
        /*
         * Regardless of what method was used to set the UID, set fifth byte and modify
         * the ATQA for 4 or 7-byte UID
         */
-
        rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
-       if(_7BUID)
-       {
+       if (_7BUID) {
                rATQA[0] = 0x44;
                rUIDBCC1[0] = 0x88;
+               rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
                rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
        }
 
-       // start mkseconds counter
-       StartCountUS();
-
-       // We need to listen to the high-frequency, peak-detected path.
-       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-       FpgaSetupSsc();
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-       SpinDelay(200);
-
        if (MF_DBGLEVEL >= 1)   {
                if (!_7BUID) {
-                       Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
-               }else
-               {
-                       Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
+                       Dbprintf("4B UID: %02x%02x%02x%02x", 
+                               rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
+               } else {
+                       Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
+                               rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
+                               rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
                }
        }
-       // calibrate mkseconds counter
-       GetDeltaCountUS();
-       bool finished = false;
+
+       // We need to listen to the high-frequency, peak-detected path.
+       iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+       // free eventually allocated BigBuf memory but keep Emulator Memory
+       BigBuf_free_keep_EM();
+
+       // clear trace
+       clear_trace();
+       set_tracing(TRUE);
+
+
+       bool finished = FALSE;
        while (!BUTTON_PRESS() && !finished) {
                WDT_HIT();
 
                // find reader field
-               // Vref = 3300mV, and an 10:1 voltage divider on the input
-               // can measure voltages up to 33000 mV
                if (cardSTATE == MFEMUL_NOFIELD) {
-                       vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
+                       vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
                        if (vHf > MF_MINFIELDV) {
                                cardSTATE_TO_IDLE();
                                LED_A_ON();
@@ -2251,14 +2438,15 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
                //Now, get data
 
-               res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
+               res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
                if (res == 2) { //Field is off!
                        cardSTATE = MFEMUL_NOFIELD;
                        LEDsoff();
                        continue;
-               }else if(res == 1) break;//return value 1 means button press
-
-
+               } else if (res == 1) {
+                       break;  //return value 1 means button press
+               }
+                       
                // REQ or WUP request in ANY state and WUP in HALTED state
                if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
                        selTimer = GetTickCount();
@@ -2272,11 +2460,12 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                        cardAUTHKEY = 0xff;
                        continue;
                }
-
+               
                switch (cardSTATE) {
                        case MFEMUL_NOFIELD:
                        case MFEMUL_HALTED:
                        case MFEMUL_IDLE:{
+                               LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                break;
                        }
                        case MFEMUL_SELECT1:{
@@ -2294,12 +2483,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                // select card
                                if (len == 9 && 
                                                (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
-
-                                       if (!_7BUID) 
-                                               EmSendCmd(rSAK, sizeof(rSAK));
-                                       else
-                                               EmSendCmd(rSAK1, sizeof(rSAK1));
-
+                                       EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
                                        cuid = bytes_to_num(rUIDBCC1, 4);
                                        if (!_7BUID) {
                                                cardSTATE = MFEMUL_WORK;
@@ -2308,20 +2492,20 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                                break;
                                        } else {
                                                cardSTATE = MFEMUL_SELECT2;
-                                               break;
                                        }
                                }
-                               
                                break;
                        }
                        case MFEMUL_AUTH1:{
                                if( len != 8)
                                {
                                        cardSTATE_TO_IDLE();
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                        break;
                                }
+
                                uint32_t ar = bytes_to_num(receivedCmd, 4);
-                               uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
+                               uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
 
                                //Collect AR/NR
                                if(ar_nr_collected < 2){
@@ -2341,11 +2525,15 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 
                                // test if auth OK
                                if (cardRr != prng_successor(nonce, 64)){
-                                       if (MF_DBGLEVEL >= 2)   Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
-                                       //Shouldn't we respond anything here?
+                                       if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
+                                                       cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
+                                                       cardRr, prng_successor(nonce, 64));
+                                       // Shouldn't we respond anything here?
                                        // Right now, we don't nack or anything, which causes the
                                        // reader to do a WUPA after a while. /Martin
+                                       // -- which is the correct response. /piwi
                                        cardSTATE_TO_IDLE();
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                        break;
                                }
 
@@ -2356,12 +2544,16 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
                                LED_C_ON();
                                cardSTATE = MFEMUL_WORK;
-                               if (MF_DBGLEVEL >= 4)   Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
+                               if (MF_DBGLEVEL >= 4)   Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d", 
+                                       cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
+                                       GetTickCount() - authTimer);
                                break;
                        }
                        case MFEMUL_SELECT2:{
-                               if (!len) break;
-                       
+                               if (!len) { 
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       break;
+                               }
                                if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
                                        EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
                                        break;
@@ -2371,7 +2563,6 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                if (len == 9 && 
                                                (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
                                        EmSendCmd(rSAK, sizeof(rSAK));
-
                                        cuid = bytes_to_num(rUIDBCC2, 4);
                                        cardSTATE = MFEMUL_WORK;
                                        LED_B_ON();
@@ -2380,22 +2571,28 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                
                                // i guess there is a command). go into the work state.
-                               if (len != 4) break;
+                               if (len != 4) {
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       break;
+                               }
                                cardSTATE = MFEMUL_WORK;
                                //goto lbWORK;
                                //intentional fall-through to the next case-stmt
                        }
-                       case MFEMUL_WORK:{
-                               if (len == 0) break;
 
+                       case MFEMUL_WORK:{
+                               if (len == 0) {
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       break;
+                               }
+                               
                                bool encrypted_data = (cardAUTHKEY != 0xFF) ;
 
-                               if(encrypted_data)
-                               {
+                               if(encrypted_data) {
                                        // decrypt seqence
                                        mf_crypto1_decrypt(pcs, receivedCmd, len);
                                }
-
+                               
                                if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
                                        authTimer = GetTickCount();
                                        cardAUTHSC = receivedCmd[1] / 4;  // received block num
@@ -2404,22 +2601,22 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
 
                                        if (!encrypted_data) { // first authentication
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
+                                               if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
 
                                                crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
                                                num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
-                                       }
-                                       else{ // nested authentication
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
-                                               ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
+                                       } else { // nested authentication
+                                               if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
+                                               ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
                                                num_to_bytes(ans, 4, rAUTH_AT);
                                        }
+
                                        EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
                                        //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
                                        cardSTATE = MFEMUL_AUTH1;
                                        break;
                                }
-
+                               
                                // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
                                // BUT... ACK --> NACK
                                if (len == 1 && receivedCmd[0] == CARD_ACK) {
@@ -2433,42 +2630,40 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        break;
                                }
                                
-                               if(len != 4) break;
+                               if(len != 4) {
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
+                                       break;
+                               }
 
                                if(receivedCmd[0] == 0x30 // read block
                                                || receivedCmd[0] == 0xA0 // write block
-                                               || receivedCmd[0] == 0xC0
-                                               || receivedCmd[0] == 0xC1
-                                               || receivedCmd[0] == 0xC2 // inc dec restore
-                                               || receivedCmd[0] == 0xB0) // transfer
-                               {
-                                       if (receivedCmd[1] >= 16 * 4)
-                                       {
-
+                                               || receivedCmd[0] == 0xC0 // inc
+                                               || receivedCmd[0] == 0xC1 // dec
+                                               || receivedCmd[0] == 0xC2 // restore
+                                               || receivedCmd[0] == 0xB0) { // transfer
+                                       if (receivedCmd[1] >= 16 * 4) {
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
                                                break;
                                        }
 
-                                       if (receivedCmd[1] / 4 != cardAUTHSC)
-                                       {
+                                       if (receivedCmd[1] / 4 != cardAUTHSC) {
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
-                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
+                                               if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
                                                break;
                                        }
                                }
                                // read block
                                if (receivedCmd[0] == 0x30) {
-                                       if (MF_DBGLEVEL >= 2) {
+                                       if (MF_DBGLEVEL >= 4) {
                                                Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
                                        }
                                        emlGetMem(response, receivedCmd[1], 1);
                                        AppendCrc14443a(response, 16);
-                                       mf_crypto1_encrypt(pcs, response, 18, &par);
-                                       EmSendCmdPar(response, 18, par);
+                                       mf_crypto1_encrypt(pcs, response, 18, response_par);
+                                       EmSendCmdPar(response, 18, response_par);
                                        numReads++;
-                                       if(exitAfterNReads > 0 && numReads == exitAfterNReads)
-                                       {
+                                       if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
                                                Dbprintf("%d reads done, exiting", numReads);
                                                finished = true;
                                        }
@@ -2476,18 +2671,15 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                }
                                // write block
                                if (receivedCmd[0] == 0xA0) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
-
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
                                        EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
-                                       //nextCycleTimeout = 50;
                                        cardSTATE = MFEMUL_WRITEBL2;
                                        cardWRBL = receivedCmd[1];
                                        break;
-                               }                               
+                               }
                                // increment, decrement, restore
                                if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
-
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
                                        if (emlCheckValBl(receivedCmd[1])) {
                                                if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
@@ -2501,28 +2693,24 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        if (receivedCmd[0] == 0xC2)
                                                cardSTATE = MFEMUL_INTREG_REST;
                                        cardWRBL = receivedCmd[1];
-
                                        break;
                                }
-                               
                                // transfer
                                if (receivedCmd[0] == 0xB0) {
-                                       if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
-                                       
+                                       if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
                                        if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
                                        else
                                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
-                                               
                                        break;
                                }
-
                                // halt
                                if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
                                        LED_B_OFF();
                                        LED_C_OFF();
                                        cardSTATE = MFEMUL_HALTED;
                                        if (MF_DBGLEVEL >= 4)   Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                        break;
                                }
                                // RATS
@@ -2530,12 +2718,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
                                        break;
                                }
-
                                // command not allowed
                                if (MF_DBGLEVEL >= 4)   Dbprintf("Received command not allowed, nacking");
                                EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
-
-                               // case break
                                break;
                        }
                        case MFEMUL_WRITEBL2:{
@@ -2544,10 +2729,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        emlSetMem(receivedCmd, cardWRBL, 1);
                                        EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
                                        cardSTATE = MFEMUL_WORK;
-                                       break;
                                } else {
                                        cardSTATE_TO_IDLE();
-                                       break;
+                                       LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                }
                                break;
                        }
@@ -2559,7 +2743,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
                                        cardSTATE_TO_IDLE();
                                        break;
-                               }
+                               } 
+                               LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                cardINTREG = cardINTREG + ans;
                                cardSTATE = MFEMUL_WORK;
                                break;
@@ -2572,6 +2757,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        cardSTATE_TO_IDLE();
                                        break;
                                }
+                               LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                cardINTREG = cardINTREG - ans;
                                cardSTATE = MFEMUL_WORK;
                                break;
@@ -2584,6 +2770,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                                        cardSTATE_TO_IDLE();
                                        break;
                                }
+                               LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                                cardSTATE = MFEMUL_WORK;
                                break;
                        }
@@ -2593,33 +2780,28 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LEDsoff();
 
-       // add trace trailer
-       memset(rAUTH_NT, 0x44, 4);
-       LogTrace(rAUTH_NT, 4, 0, 0, TRUE);
        if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
        {
                //May just aswell send the collected ar_nr in the response aswell
                cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
        }
+
        if(flags & FLAG_NR_AR_ATTACK)
        {
-               if(ar_nr_collected > 1)
-               {
+               if(ar_nr_collected > 1) {
                        Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
-                       Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x",
-                                        ar_nr_responses[0], // UID
+                       Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
+                                       ar_nr_responses[0], // UID
                                        ar_nr_responses[1], //NT
                                        ar_nr_responses[2], //AR1
                                        ar_nr_responses[3], //NR1
                                        ar_nr_responses[6], //AR2
                                        ar_nr_responses[7] //NR2
                                        );
-               }else
-               {
+               } else {
                        Dbprintf("Failed to obtain two AR/NR pairs!");
-                       if(ar_nr_collected >0)
-                       {
-                               Dbprintf("Only got these: UID=%08d, nonce=%08d, AR1=%08d, NR1=%08d",
+                       if(ar_nr_collected >0) {
+                               Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
                                                ar_nr_responses[0], // UID
                                                ar_nr_responses[1], //NT
                                                ar_nr_responses[2], //AR1
@@ -2628,7 +2810,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                        }
                }
        }
-       if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",    tracing, traceLen);
+       if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",    tracing, BigBuf_get_traceLen());
+       
 }
 
 
@@ -2645,85 +2828,88 @@ void RAMFUNC SniffMifare(uint8_t param) {
        // C(red) A(yellow) B(green)
        LEDsoff();
        // init trace buffer
-    iso14a_clear_trace();
+       clear_trace();
+       set_tracing(TRUE);
 
        // The command (reader -> tag) that we're receiving.
        // The length of a received command will in most cases be no more than 18 bytes.
        // So 32 should be enough!
-       uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+       uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
+       uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
        // The response (tag -> reader) that we're receiving.
-       uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
+       uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
+       uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
 
-       // As we receive stuff, we copy it from receivedCmd or receivedResponse
-       // into trace, along with its length and other annotations.
-       //uint8_t *trace = (uint8_t *)BigBuf;
-       
-       // The DMA buffer, used to stream samples from the FPGA
-       int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
-       int8_t *data = dmaBuf;
+       iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
+       // free eventually allocated BigBuf memory
+       BigBuf_free();
+       // allocate the DMA buffer, used to stream samples from the FPGA
+       uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
+       uint8_t *data = dmaBuf;
+       uint8_t previous_data = 0;
        int maxDataLen = 0;
        int dataLen = 0;
+       bool ReaderIsActive = FALSE;
+       bool TagIsActive = FALSE;
 
        // Set up the demodulator for tag -> reader responses.
-       Demod.output = receivedResponse;
-       Demod.len = 0;
-       Demod.state = DEMOD_UNSYNCD;
+       DemodInit(receivedResponse, receivedResponsePar);
 
        // Set up the demodulator for the reader -> tag commands
-       memset(&Uart, 0, sizeof(Uart));
-       Uart.output = receivedCmd;
-       Uart.byteCntMax = 32; // was 100 (greg)//////////////////
-       Uart.state = STATE_UNSYNCD;
+       UartInit(receivedCmd, receivedCmdPar);
 
        // Setup for the DMA.
-       FpgaSetupSsc();
-       FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
+       FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
 
-       // And put the FPGA in the appropriate mode
-       // Signal field is off with the appropriate LED
        LED_D_OFF();
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
-       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
        
        // init sniffer
        MfSniffInit();
-       int sniffCounter = 0;
 
        // And now we loop, receiving samples.
-       while(true) {
+       for(uint32_t sniffCounter = 0; TRUE; ) {
+       
                if(BUTTON_PRESS()) {
                        DbpString("cancelled by button");
-                       goto done;
+                       break;
                }
 
                LED_A_ON();
                WDT_HIT();
                
-               if (++sniffCounter > 65) {
-                       if (MfSniffSend(2000)) {
-                               FpgaEnableSscDma();
+               if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
+                       // check if a transaction is completed (timeout after 2000ms).
+                       // if yes, stop the DMA transfer and send what we have so far to the client
+                       if (MfSniffSend(2000)) {                        
+                               // Reset everything - we missed some sniffed data anyway while the DMA was stopped
+                               sniffCounter = 0;
+                               data = dmaBuf;
+                               maxDataLen = 0;
+                               ReaderIsActive = FALSE;
+                               TagIsActive = FALSE;
+                               FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
                        }
-                       sniffCounter = 0;
                }
-
-               int register readBufDataP = data - dmaBuf;
-               int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
-               if (readBufDataP <= dmaBufDataP){
-                       dataLen = dmaBufDataP - readBufDataP;
-               } else {
-                       dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
+               
+               int register readBufDataP = data - dmaBuf;      // number of bytes we have processed so far
+               int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
+               if (readBufDataP <= dmaBufDataP){                       // we are processing the same block of data which is currently being transferred
+                       dataLen = dmaBufDataP - readBufDataP;   // number of bytes still to be processed
+               } else {                                                                        
+                       dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
                }
                // test for length of buffer
-               if(dataLen > maxDataLen) {
-                       maxDataLen = dataLen;
-                       if(dataLen > 400) {
+               if(dataLen > maxDataLen) {                                      // we are more behind than ever...
+                       maxDataLen = dataLen;                                   
+                       if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
                                Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
-                               goto done;
+                               break;
                        }
                }
                if(dataLen < 1) continue;
 
-               // primary buffer was stopped( <-- we lost data!
+               // primary buffer was stopped ( <-- we lost data!
                if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
                        AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
                        AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
@@ -2737,44 +2923,53 @@ void RAMFUNC SniffMifare(uint8_t param) {
 
                LED_A_OFF();
                
-               if(MillerDecoding((data[0] & 0xF0) >> 4)) {
-                       LED_C_INV();
-                       // check - if there is a short 7bit request from reader
-                       if (MfSniffLogic(receivedCmd, Uart.byteCnt, Uart.parityBits, Uart.bitCnt, TRUE)) break;
-
-                       /* And ready to receive another command. */
-                       Uart.state = STATE_UNSYNCD;
-                       
-                       /* And also reset the demod code */
-                       Demod.state = DEMOD_UNSYNCD;
-               }
+               if (sniffCounter & 0x01) {
 
-               if(ManchesterDecoding(data[0], 0)) {
-                       LED_C_INV();
+                       if(!TagIsActive) {              // no need to try decoding tag data if the reader is sending
+                               uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+                               if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
+                                       LED_C_INV();
+                                       if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
 
-                       if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
+                                       /* And ready to receive another command. */
+                                       UartInit(receivedCmd, receivedCmdPar);
+                                       
+                                       /* And also reset the demod code */
+                                       DemodReset();
+                               }
+                               ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+                       }
+                       
+                       if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending
+                               uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+                               if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
+                                       LED_C_INV();
 
-                       // And ready to receive another response.
-                       memset(&Demod, 0, sizeof(Demod));
-                       Demod.output = receivedResponse;
-                       Demod.state = DEMOD_UNSYNCD;
+                                       if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
 
-                       /* And also reset the uart code */
-                       Uart.state = STATE_UNSYNCD;
+                                       // And ready to receive another response.
+                                       DemodReset();
+                                       // And reset the Miller decoder including its (now outdated) input buffer
+                                       UartInit(receivedCmd, receivedCmdPar);
+                               }
+                               TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+                       }
                }
 
+               previous_data = *data;
+               sniffCounter++;
                data++;
-               if(data > dmaBuf + DMA_BUFFER_SIZE) {
+               if(data == dmaBuf + DMA_BUFFER_SIZE) {
                        data = dmaBuf;
                }
+
        } // main cycle
 
        DbpString("COMMAND FINISHED");
 
-done:
        FpgaDisableSscDma();
        MfSniffEnd();
        
-       Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax);
+       Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
        LEDsoff();
 }
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