X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/9ab7a6c75566a2d06e56a8a97173c6382a3c5b3d..refs/pull/969/head:/armsrc/iso15693.c?ds=sidebyside

diff --git a/armsrc/iso15693.c b/armsrc/iso15693.c
index 31c13e95..f16698bb 100644
--- a/armsrc/iso15693.c
+++ b/armsrc/iso15693.c
@@ -1,320 +1,1880 @@
 //-----------------------------------------------------------------------------
-// Routines to support ISO 15693. This includes both the reader software and
-// the `fake tag' modes, but at the moment I've implemented only the reader
-// stuff, and that barely.
 // Jonathan Westhues, split Nov 2006
+// Modified by Greg Jones, Jan 2009
+// Modified by Adrian Dabrowski "atrox", Mar-Sept 2010,Oct 2011
+// Modified by piwi, Oct 2018
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Routines to support ISO 15693. This includes both the reader software and
+// the `fake tag' modes.
+//-----------------------------------------------------------------------------
+
+// The ISO 15693 describes two transmission modes from reader to tag, and four
+// transmission modes from tag to reader. As of Oct 2018 this code supports
+// both reader modes and the high speed variant with one subcarrier from card to reader.
+// As long as the card fully support ISO 15693 this is no problem, since the
+// reader chooses both data rates, but some non-standard tags do not.
+// For card simulation, the code supports both high and low speed modes with one subcarrier.
+//
+// VCD (reader) -> VICC (tag)
+// 1 out of 256:
+//  data rate: 1,66 kbit/s (fc/8192)
+//  used for long range
+// 1 out of 4:
+//  data rate: 26,48 kbit/s (fc/512)
+//  used for short range, high speed
+//
+// VICC (tag) -> VCD (reader)
+// Modulation:
+//      ASK / one subcarrier (423,75 khz)
+//      FSK / two subcarriers (423,75 khz && 484,28 khz)
+// Data Rates / Modes:
+//  low ASK: 6,62 kbit/s
+//  low FSK: 6.67 kbit/s
+//  high ASK: 26,48 kbit/s
+//  high FSK: 26,69 kbit/s
+//-----------------------------------------------------------------------------
+
+
+// Random Remarks:
+// *) UID is always used "transmission order" (LSB), which is reverse to display order
+
+// TODO / BUGS / ISSUES:
+// *) signal decoding is unable to detect collisions.
+// *) add anti-collision support for inventory-commands
+// *) read security status of a block
+// *) sniffing and simulation do not support two subcarrier modes.
+// *) remove or refactor code under "deprecated"
+// *) document all the functions
+
+#include "iso15693.h"
+
+#include "proxmark3.h"
+#include "util.h"
+#include "apps.h"
+#include "string.h"
+#include "iso15693tools.h"
+#include "protocols.h"
+#include "usb_cdc.h"
+#include "BigBuf.h"
+#include "fpgaloader.h"
+
+#define arraylen(x) (sizeof(x)/sizeof((x)[0]))
+
+// Delays in SSP_CLK ticks.
+// SSP_CLK runs at 13,56MHz / 32 = 423.75kHz when simulating a tag
+#define DELAY_READER_TO_ARM               8
+#define DELAY_ARM_TO_READER               0
+//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when acting as reader. All values should be multiples of 16
+#define DELAY_ARM_TO_TAG                 16
+#define DELAY_TAG_TO_ARM                 32
+//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when snooping. All values should be multiples of 16
+#define DELAY_TAG_TO_ARM_SNOOP           32
+#define DELAY_READER_TO_ARM_SNOOP        32
+
+// times in samples @ 212kHz when acting as reader
+//#define ISO15693_READER_TIMEOUT              80 // 80/212kHz = 378us, nominal t1_max=313,9us
+#define ISO15693_READER_TIMEOUT             330 // 330/212kHz = 1558us, should be even enough for iClass tags responding to ACTALL
+#define ISO15693_READER_TIMEOUT_WRITE      4700 // 4700/212kHz = 22ms, nominal 20ms
+
+
+static int DEBUG = 0;
+
+
+///////////////////////////////////////////////////////////////////////
+// ISO 15693 Part 2 - Air Interface
+// This section basically contains transmission and receiving of bits
+///////////////////////////////////////////////////////////////////////
+
+// buffers
+#define ISO15693_DMA_BUFFER_SIZE        256 // must be a power of 2
+#define ISO15693_MAX_RESPONSE_LENGTH     36 // allows read single block with the maximum block size of 256bits. Read multiple blocks not supported yet
+#define ISO15693_MAX_COMMAND_LENGTH      45 // allows write single block with the maximum block size of 256bits. Write multiple blocks not supported yet
+
+
+// specific LogTrace function for ISO15693: the duration needs to be scaled because otherwise it won't fit into a uint16_t
+bool LogTrace_ISO15693(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag) {
+	uint32_t duration = timestamp_end - timestamp_start;
+	duration /= 32;
+	timestamp_end = timestamp_start + duration;
+	return LogTrace(btBytes, iLen, timestamp_start, timestamp_end, parity, readerToTag);
+}
+
+
+// ---------------------------
+// Signal Processing
+// ---------------------------
+
+// prepare data using "1 out of 4" code for later transmission
+// resulting data rate is 26.48 kbit/s (fc/512)
+// cmd ... data
+// n ... length of data
+void CodeIso15693AsReader(uint8_t *cmd, int n) {
+
+	ToSendReset();
+
+	// SOF for 1of4
+	ToSend[++ToSendMax] = 0x84; //10000100
+
+	// data
+	for (int i = 0; i < n; i++) {
+		for (int j = 0; j < 8; j += 2) {
+			int these = (cmd[i] >> j) & 0x03;
+			switch(these) {
+				case 0:
+					ToSend[++ToSendMax] = 0x40; //01000000
+					break;
+				case 1:
+					ToSend[++ToSendMax] = 0x10; //00010000
+					break;
+				case 2:
+					ToSend[++ToSendMax] = 0x04; //00000100
+					break;
+				case 3:
+					ToSend[++ToSendMax] = 0x01; //00000001
+					break;
+			}
+		}
+	}
+
+	// EOF
+	ToSend[++ToSendMax] = 0x20; //0010 + 0000 padding
+
+	ToSendMax++;
+}
+
+
+// Encode EOF only
+static void CodeIso15693AsReaderEOF() {
+	ToSendReset();
+	ToSend[++ToSendMax] = 0x20;
+	ToSendMax++;
+}
+
+
+// encode data using "1 out of 256" scheme
+// data rate is 1,66 kbit/s (fc/8192)
+// is designed for more robust communication over longer distances
+static void CodeIso15693AsReader256(uint8_t *cmd, int n)
+{
+	ToSendReset();
+
+	// SOF for 1of256
+	ToSend[++ToSendMax] = 0x81; //10000001
+
+	// data
+	for(int i = 0; i < n; i++) {
+		for (int j = 0; j <= 255; j++) {
+			if (cmd[i] == j) {
+				ToSendStuffBit(0);
+				ToSendStuffBit(1);
+			} else {
+				ToSendStuffBit(0);
+				ToSendStuffBit(0);
+			}
+		}
+	}
+
+	// EOF
+	ToSend[++ToSendMax] = 0x20; //0010 + 0000 padding
+
+	ToSendMax++;
+}
+
+
+// static uint8_t encode4Bits(const uint8_t b) {
+	// uint8_t c = b & 0xF;
+	// // OTA, the least significant bits first
+	// //         The columns are
+	// //               1 - Bit value to send
+	// //               2 - Reversed (big-endian)
+	// //               3 - Manchester Encoded
+	// //               4 - Hex values
+
+	// switch(c){
+	// //                          1       2         3         4
+	  // case 15: return 0x55; // 1111 -> 1111 -> 01010101 -> 0x55
+	  // case 14: return 0x95; // 1110 -> 0111 -> 10010101 -> 0x95
+	  // case 13: return 0x65; // 1101 -> 1011 -> 01100101 -> 0x65
+	  // case 12: return 0xa5; // 1100 -> 0011 -> 10100101 -> 0xa5
+	  // case 11: return 0x59; // 1011 -> 1101 -> 01011001 -> 0x59
+	  // case 10: return 0x99; // 1010 -> 0101 -> 10011001 -> 0x99
+	  // case 9:  return 0x69; // 1001 -> 1001 -> 01101001 -> 0x69
+	  // case 8:  return 0xa9; // 1000 -> 0001 -> 10101001 -> 0xa9
+	  // case 7:  return 0x56; // 0111 -> 1110 -> 01010110 -> 0x56
+	  // case 6:  return 0x96; // 0110 -> 0110 -> 10010110 -> 0x96
+	  // case 5:  return 0x66; // 0101 -> 1010 -> 01100110 -> 0x66
+	  // case 4:  return 0xa6; // 0100 -> 0010 -> 10100110 -> 0xa6
+	  // case 3:  return 0x5a; // 0011 -> 1100 -> 01011010 -> 0x5a
+	  // case 2:  return 0x9a; // 0010 -> 0100 -> 10011010 -> 0x9a
+	  // case 1:  return 0x6a; // 0001 -> 1000 -> 01101010 -> 0x6a
+	  // default: return 0xaa; // 0000 -> 0000 -> 10101010 -> 0xaa
+
+	// }
+// }
+
+static const uint8_t encode_4bits[16] = { 0xaa, 0x6a, 0x9a, 0x5a, 0xa6, 0x66, 0x96, 0x56, 0xa9, 0x69, 0x99, 0x59, 0xa5, 0x65, 0x95, 0x55 };
+
+void CodeIso15693AsTag(uint8_t *cmd, size_t len) {
+	/*
+	 * SOF comprises 3 parts;
+	 * * An unmodulated time of 56.64 us
+	 * * 24 pulses of 423.75 kHz (fc/32)
+	 * * A logic 1, which starts with an unmodulated time of 18.88us
+	 *   followed by 8 pulses of 423.75kHz (fc/32)
+	 *
+	 * EOF comprises 3 parts:
+	 * - A logic 0 (which starts with 8 pulses of fc/32 followed by an unmodulated
+	 *   time of 18.88us.
+	 * - 24 pulses of fc/32
+	 * - An unmodulated time of 56.64 us
+	 *
+	 * A logic 0 starts with 8 pulses of fc/32
+	 * followed by an unmodulated time of 256/fc (~18,88us).
+	 *
+	 * A logic 0 starts with unmodulated time of 256/fc (~18,88us) followed by
+	 * 8 pulses of fc/32 (also 18.88us)
+	 *
+	 * A bit here becomes 8 pulses of fc/32. Therefore:
+	 * The SOF can be written as 00011101 = 0x1D
+	 * The EOF can be written as 10111000 = 0xb8
+	 * A logic 1 is 01
+	 * A logic 0 is 10
+	 *
+	 * */
+
+	ToSendReset();
+
+	// SOF
+	ToSend[++ToSendMax] = 0x1D;  // 00011101
+
+	// data
+	for (int i = 0; i < len; i++) {
+		ToSend[++ToSendMax] = encode_4bits[cmd[i] & 0xF];
+		ToSend[++ToSendMax] = encode_4bits[cmd[i] >> 4];
+	}
+
+	// EOF
+	ToSend[++ToSendMax] = 0xB8; // 10111000
+
+	ToSendMax++;
+}
+
+
+// Transmit the command (to the tag) that was placed in cmd[].
+void TransmitTo15693Tag(const uint8_t *cmd, int len, uint32_t *start_time) {
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_FULL_MOD);
+
+	if (*start_time < DELAY_ARM_TO_TAG) {
+		*start_time = DELAY_ARM_TO_TAG;
+	}
+
+	*start_time = (*start_time - DELAY_ARM_TO_TAG) & 0xfffffff0;
+
+	if (GetCountSspClk() > *start_time) { // we may miss the intended time
+		*start_time = (GetCountSspClk() + 16) & 0xfffffff0; // next possible time
+	}
+
+	while (GetCountSspClk() < *start_time)
+		/* wait */ ;
+
+	LED_B_ON();
+	for (int c = 0; c < len; c++) {
+		uint8_t data = cmd[c];
+		for (int i = 0; i < 8; i++) {
+			uint16_t send_word = (data & 0x80) ? 0xffff : 0x0000;
+			while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
+			AT91C_BASE_SSC->SSC_THR = send_word;
+			while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
+			AT91C_BASE_SSC->SSC_THR = send_word;
+			data <<= 1;
+		}
+		WDT_HIT();
+	}
+	LED_B_OFF();
+
+	*start_time = *start_time + DELAY_ARM_TO_TAG;
+}
+
+
+//-----------------------------------------------------------------------------
+// Transmit the tag response (to the reader) that was placed in cmd[].
+//-----------------------------------------------------------------------------
+void TransmitTo15693Reader(const uint8_t *cmd, size_t len, uint32_t *start_time, uint32_t slot_time, bool slow) {
+	// don't use the FPGA_HF_SIMULATOR_MODULATE_424K_8BIT minor mode. It would spoil GetCountSspClk()
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_424K);
+
+	uint32_t modulation_start_time = *start_time - DELAY_ARM_TO_READER + 3 * 8;  // no need to transfer the unmodulated start of SOF
+
+	while (GetCountSspClk() > (modulation_start_time & 0xfffffff8) + 3) { // we will miss the intended time
+		if (slot_time) {
+			modulation_start_time += slot_time; // use next available slot
+		} else {
+			modulation_start_time = (modulation_start_time & 0xfffffff8) + 8; // next possible time
+		}
+	}
+
+	while (GetCountSspClk() < (modulation_start_time & 0xfffffff8))
+		/* wait */ ;
+
+	uint8_t shift_delay = modulation_start_time & 0x00000007;
+
+	*start_time = modulation_start_time + DELAY_ARM_TO_READER - 3 * 8;
+
+	LED_C_ON();
+	uint8_t bits_to_shift = 0x00;
+	uint8_t bits_to_send = 0x00;
+	for (size_t c = 0; c < len; c++) {
+		for (int i = (c==0?4:7); i >= 0; i--) {
+			uint8_t cmd_bits = ((cmd[c] >> i) & 0x01) ? 0xff : 0x00;
+			for (int j = 0; j < (slow?4:1); ) {
+				if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+					bits_to_send = bits_to_shift << (8 - shift_delay) | cmd_bits >> shift_delay;
+					AT91C_BASE_SSC->SSC_THR = bits_to_send;
+					bits_to_shift = cmd_bits;
+					j++;
+				}
+			}
+		}
+		WDT_HIT();
+	}
+	// send the remaining bits, padded with 0:
+	bits_to_send = bits_to_shift << (8 - shift_delay);
+	for ( ; ; ) {
+		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+			AT91C_BASE_SSC->SSC_THR = bits_to_send;
+			break;
+		}
+	}
+	LED_C_OFF();
+}
+
+
+//=============================================================================
+// An ISO 15693 decoder for tag responses (one subcarrier only).
+// Uses cross correlation to identify each bit and EOF.
+// This function is called 8 times per bit (every 2 subcarrier cycles).
+// Subcarrier frequency fs is 424kHz, 1/fs = 2,36us,
+// i.e. function is called every 4,72us
+// LED handling:
+//    LED C -> ON once we have received the SOF and are expecting the rest.
+//    LED C -> OFF once we have received EOF or are unsynced
+//
+// Returns: true if we received a EOF
+//          false if we are still waiting for some more
+//=============================================================================
+
+#define NOISE_THRESHOLD          80                   // don't try to correlate noise
+#define MAX_PREVIOUS_AMPLITUDE   (-1 - NOISE_THRESHOLD)
+
+typedef struct DecodeTag {
+	enum {
+		STATE_TAG_SOF_LOW,
+		STATE_TAG_SOF_RISING_EDGE,
+		STATE_TAG_SOF_HIGH,
+		STATE_TAG_SOF_HIGH_END,
+		STATE_TAG_RECEIVING_DATA,
+		STATE_TAG_EOF,
+		STATE_TAG_EOF_TAIL
+	}         state;
+	int       bitCount;
+	int       posCount;
+	enum {
+		LOGIC0,
+		LOGIC1,
+		SOF_PART1,
+		SOF_PART2
+	}         lastBit;
+	uint16_t  shiftReg;
+	uint16_t  max_len;
+	uint8_t   *output;
+	int       len;
+	int       sum1, sum2;
+	int       threshold_sof;
+	int       threshold_half;
+	uint16_t  previous_amplitude;
+} DecodeTag_t;
+
+
+static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag) {
+	switch (DecodeTag->state) {
+		case STATE_TAG_SOF_LOW:
+			// waiting for a rising edge
+			if (amplitude > NOISE_THRESHOLD + DecodeTag->previous_amplitude) {
+				if (DecodeTag->posCount > 10) {
+					DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude; // to be divided by 2
+					DecodeTag->threshold_half = 0;
+					DecodeTag->state = STATE_TAG_SOF_RISING_EDGE;
+				} else {
+					DecodeTag->posCount = 0;
+				}
+			} else {
+				DecodeTag->posCount++;
+				DecodeTag->previous_amplitude = amplitude;
+			}
+			break;
+
+		case STATE_TAG_SOF_RISING_EDGE:
+			if (amplitude > DecodeTag->threshold_sof + DecodeTag->previous_amplitude) { // edge still rising
+				if (amplitude > DecodeTag->threshold_sof + DecodeTag->threshold_sof) { // steeper edge, take this as time reference
+					DecodeTag->posCount = 1;
+				} else {
+					DecodeTag->posCount = 2;
+				}
+				DecodeTag->threshold_sof = (amplitude - DecodeTag->previous_amplitude) / 2;
+			} else {
+				DecodeTag->posCount = 2;
+				DecodeTag->threshold_sof = DecodeTag->threshold_sof/2;
+			}
+			// DecodeTag->posCount = 2;
+			DecodeTag->state = STATE_TAG_SOF_HIGH;
+			break;
+
+		case STATE_TAG_SOF_HIGH:
+			// waiting for 10 times high. Take average over the last 8
+			if (amplitude > DecodeTag->threshold_sof) {
+				DecodeTag->posCount++;
+				if (DecodeTag->posCount > 2) {
+					DecodeTag->threshold_half += amplitude; // keep track of average high value
+				}
+				if (DecodeTag->posCount == 10) {
+					DecodeTag->threshold_half >>= 2; // (4 times 1/2 average)
+					DecodeTag->state = STATE_TAG_SOF_HIGH_END;
+				}
+			} else { // high phase was too short
+				DecodeTag->posCount = 1;
+				DecodeTag->previous_amplitude = amplitude;
+				DecodeTag->state = STATE_TAG_SOF_LOW;
+			}
+			break;
+
+		case STATE_TAG_SOF_HIGH_END:
+			// check for falling edge
+			if (DecodeTag->posCount == 13 && amplitude < DecodeTag->threshold_sof) {
+				DecodeTag->lastBit = SOF_PART1;  // detected 1st part of SOF (12 samples low and 12 samples high)
+				DecodeTag->shiftReg = 0;
+				DecodeTag->bitCount = 0;
+				DecodeTag->len = 0;
+				DecodeTag->sum1 = amplitude;
+				DecodeTag->sum2 = 0;
+				DecodeTag->posCount = 2;
+				DecodeTag->state = STATE_TAG_RECEIVING_DATA;
+				// FpgaDisableTracing(); // DEBUGGING
+				// Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
+					// amplitude,
+					// DecodeTag->threshold_sof,
+					// DecodeTag->threshold_half/4,
+					// DecodeTag->previous_amplitude); // DEBUGGING
+				LED_C_ON();
+			} else {
+				DecodeTag->posCount++;
+				if (DecodeTag->posCount > 13) { // high phase too long
+					DecodeTag->posCount = 0;
+					DecodeTag->previous_amplitude = amplitude;
+					DecodeTag->state = STATE_TAG_SOF_LOW;
+					LED_C_OFF();
+				}
+			}
+			break;
+
+		case STATE_TAG_RECEIVING_DATA:
+				// FpgaDisableTracing(); // DEBUGGING
+				// Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
+					// amplitude,
+					// DecodeTag->threshold_sof,
+					// DecodeTag->threshold_half/4,
+					// DecodeTag->previous_amplitude); // DEBUGGING
+			if (DecodeTag->posCount == 1) {
+				DecodeTag->sum1 = 0;
+				DecodeTag->sum2 = 0;
+			}
+			if (DecodeTag->posCount <= 4) {
+				DecodeTag->sum1 += amplitude;
+			} else {
+				DecodeTag->sum2 += amplitude;
+			}
+			if (DecodeTag->posCount == 8) {
+				if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in both halves
+					if (DecodeTag->lastBit == LOGIC0) {  // this was already part of EOF
+						DecodeTag->state = STATE_TAG_EOF;
+					} else {
+						DecodeTag->posCount = 0;
+						DecodeTag->previous_amplitude = amplitude;
+						DecodeTag->state = STATE_TAG_SOF_LOW;
+						LED_C_OFF();
+					}
+				} else if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in second half
+					// logic 1
+					if (DecodeTag->lastBit == SOF_PART1) { // still part of SOF
+						DecodeTag->lastBit = SOF_PART2;    // SOF completed
+					} else {
+						DecodeTag->lastBit = LOGIC1;
+						DecodeTag->shiftReg >>= 1;
+						DecodeTag->shiftReg |= 0x80;
+						DecodeTag->bitCount++;
+						if (DecodeTag->bitCount == 8) {
+							DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg;
+							DecodeTag->len++;
+							// if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING
+							if (DecodeTag->len > DecodeTag->max_len) {
+								// buffer overflow, give up
+								LED_C_OFF();
+								return true;
+							}
+							DecodeTag->bitCount = 0;
+							DecodeTag->shiftReg = 0;
+						}
+					}
+				} else if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half
+					// logic 0
+					if (DecodeTag->lastBit == SOF_PART1) { // incomplete SOF
+						DecodeTag->posCount = 0;
+						DecodeTag->previous_amplitude = amplitude;
+						DecodeTag->state = STATE_TAG_SOF_LOW;
+						LED_C_OFF();
+					} else {
+						DecodeTag->lastBit = LOGIC0;
+						DecodeTag->shiftReg >>= 1;
+						DecodeTag->bitCount++;
+						if (DecodeTag->bitCount == 8) {
+							DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg;
+							DecodeTag->len++;
+							// if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING
+							if (DecodeTag->len > DecodeTag->max_len) {
+								// buffer overflow, give up
+								DecodeTag->posCount = 0;
+								DecodeTag->previous_amplitude = amplitude;
+								DecodeTag->state = STATE_TAG_SOF_LOW;
+								LED_C_OFF();
+							}
+							DecodeTag->bitCount = 0;
+							DecodeTag->shiftReg = 0;
+						}
+					}
+				} else { // no modulation
+					if (DecodeTag->lastBit == SOF_PART2) { // only SOF (this is OK for iClass)
+						LED_C_OFF();
+						return true;
+					} else {
+						DecodeTag->posCount = 0;
+						DecodeTag->state = STATE_TAG_SOF_LOW;
+						LED_C_OFF();
+					}
+				}
+				DecodeTag->posCount = 0;
+			}
+			DecodeTag->posCount++;
+			break;
+
+		case STATE_TAG_EOF:
+			if (DecodeTag->posCount == 1) {
+				DecodeTag->sum1 = 0;
+				DecodeTag->sum2 = 0;
+			}
+			if (DecodeTag->posCount <= 4) {
+				DecodeTag->sum1 += amplitude;
+			} else {
+				DecodeTag->sum2 += amplitude;
+			}
+			if (DecodeTag->posCount == 8) {
+				if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half
+					DecodeTag->posCount = 0;
+					DecodeTag->state = STATE_TAG_EOF_TAIL;
+				} else {
+					DecodeTag->posCount = 0;
+					DecodeTag->previous_amplitude = amplitude;
+					DecodeTag->state = STATE_TAG_SOF_LOW;
+					LED_C_OFF();
+				}
+			}
+			DecodeTag->posCount++;
+			break;
+
+		case STATE_TAG_EOF_TAIL:
+			if (DecodeTag->posCount == 1) {
+				DecodeTag->sum1 = 0;
+				DecodeTag->sum2 = 0;
+			}
+			if (DecodeTag->posCount <= 4) {
+				DecodeTag->sum1 += amplitude;
+			} else {
+				DecodeTag->sum2 += amplitude;
+			}
+			if (DecodeTag->posCount == 8) {
+				if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // no modulation in both halves
+					LED_C_OFF();
+					return true;
+				} else {
+					DecodeTag->posCount = 0;
+					DecodeTag->previous_amplitude = amplitude;
+					DecodeTag->state = STATE_TAG_SOF_LOW;
+					LED_C_OFF();
+				}
+			}
+			DecodeTag->posCount++;
+			break;
+	}
+
+	return false;
+}
+
+
+static void DecodeTagInit(DecodeTag_t *DecodeTag, uint8_t *data, uint16_t max_len) {
+	DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE;
+	DecodeTag->posCount = 0;
+	DecodeTag->state = STATE_TAG_SOF_LOW;
+	DecodeTag->output = data;
+	DecodeTag->max_len = max_len;
+}
+
+
+static void DecodeTagReset(DecodeTag_t *DecodeTag) {
+	DecodeTag->posCount = 0;
+	DecodeTag->state = STATE_TAG_SOF_LOW;
+	DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE;
+}
+
+
+/*
+ *  Receive and decode the tag response, also log to tracebuffer
+ */
+int GetIso15693AnswerFromTag(uint8_t* response, uint16_t max_len, uint16_t timeout, uint32_t *eof_time) {
+
+	int samples = 0;
+	int ret = 0;
+
+	uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE];
+
+	// the Decoder data structure
+	DecodeTag_t DecodeTag = { 0 };
+	DecodeTagInit(&DecodeTag, response, max_len);
+
+	// wait for last transfer to complete
+	while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY));
+
+	// And put the FPGA in the appropriate mode
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE);
+
+	// Setup and start DMA.
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
+	FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+	uint32_t dma_start_time = 0;
+	uint16_t *upTo = dmaBuf;
+
+	for(;;) {
+		uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1);
+
+		if (behindBy == 0) continue;
+
+		samples++;
+		if (samples == 1) {
+			// DMA has transferred the very first data
+			dma_start_time = GetCountSspClk() & 0xfffffff0;
+		}
+
+		uint16_t tagdata = *upTo++;
+
+		if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {                // we have read all of the DMA buffer content.
+			upTo = dmaBuf;                                             // start reading the circular buffer from the beginning
+			if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+				Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
+				ret = -1;
+				break;
+			}
+		}
+		if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) {              // DMA Counter Register had reached 0, already rotated.
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;          // refresh the DMA Next Buffer and
+			AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE;   // DMA Next Counter registers
+		}
+
+		if (Handle15693SamplesFromTag(tagdata, &DecodeTag)) {
+			*eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM; // end of EOF
+			if (DecodeTag.lastBit == SOF_PART2) {
+				*eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS)
+			}
+			if (DecodeTag.len > DecodeTag.max_len) {
+				ret = -2; // buffer overflow
+			}
+			break;
+		}
+
+		if (samples > timeout && DecodeTag.state < STATE_TAG_RECEIVING_DATA) {
+			ret = -1;   // timeout
+			break;
+		}
+
+	}
+
+	FpgaDisableSscDma();
+
+	if (DEBUG) Dbprintf("samples = %d, ret = %d, Decoder: state = %d, lastBit = %d, len = %d, bitCount = %d, posCount = %d",
+						samples, ret, DecodeTag.state, DecodeTag.lastBit, DecodeTag.len, DecodeTag.bitCount, DecodeTag.posCount);
+
+	if (ret < 0) {
+		return ret;
+	}
+
+	uint32_t sof_time = *eof_time
+						- DecodeTag.len * 8 * 8 * 16 // time for byte transfers
+						- 32 * 16  // time for SOF transfer
+						- (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer
+
+	if (DEBUG) Dbprintf("timing: sof_time = %d, eof_time = %d", sof_time, *eof_time);
+
+	LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, *eof_time*4, NULL, false);
+
+	return DecodeTag.len;
+}
+
+
+//=============================================================================
+// An ISO15693 decoder for reader commands.
+//
+// This function is called 4 times per bit (every 2 subcarrier cycles).
+// Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us
+// LED handling:
+//    LED B -> ON once we have received the SOF and are expecting the rest.
+//    LED B -> OFF once we have received EOF or are in error state or unsynced
+//
+// Returns: true  if we received a EOF
+//          false if we are still waiting for some more
+//=============================================================================
+
+typedef struct DecodeReader {
+	enum {
+		STATE_READER_UNSYNCD,
+		STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF,
+		STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF,
+		STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF,
+		STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF,
+		STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4,
+		STATE_READER_RECEIVE_DATA_1_OUT_OF_4,
+		STATE_READER_RECEIVE_DATA_1_OUT_OF_256,
+		STATE_READER_RECEIVE_JAMMING
+	}           state;
+	enum {
+		CODING_1_OUT_OF_4,
+		CODING_1_OUT_OF_256
+	}           Coding;
+	uint8_t     shiftReg;
+	uint8_t     bitCount;
+	int         byteCount;
+	int         byteCountMax;
+	int         posCount;
+	int         sum1, sum2;
+	uint8_t     *output;
+	uint8_t     jam_search_len;
+	uint8_t     *jam_search_string;
+} DecodeReader_t;
+
+
+static void DecodeReaderInit(DecodeReader_t* DecodeReader, uint8_t *data, uint16_t max_len, uint8_t jam_search_len, uint8_t *jam_search_string) {
+	DecodeReader->output = data;
+	DecodeReader->byteCountMax = max_len;
+	DecodeReader->state = STATE_READER_UNSYNCD;
+	DecodeReader->byteCount = 0;
+	DecodeReader->bitCount = 0;
+	DecodeReader->posCount = 1;
+	DecodeReader->shiftReg = 0;
+	DecodeReader->jam_search_len = jam_search_len;
+	DecodeReader->jam_search_string = jam_search_string;
+}
+
+
+static void DecodeReaderReset(DecodeReader_t* DecodeReader) {
+	DecodeReader->state = STATE_READER_UNSYNCD;
+}
+
+
+static int inline __attribute__((always_inline)) Handle15693SampleFromReader(bool bit, DecodeReader_t *DecodeReader) {
+	switch (DecodeReader->state) {
+		case STATE_READER_UNSYNCD:
+			// wait for unmodulated carrier
+			if (bit) {
+				DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
+			}
+			break;
+
+		case STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF:
+			if (!bit) {
+				// we went low, so this could be the beginning of a SOF
+				DecodeReader->posCount = 1;
+				DecodeReader->state = STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF;
+			}
+			break;
+
+		case STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF:
+			DecodeReader->posCount++;
+			if (bit) { // detected rising edge
+				if (DecodeReader->posCount < 4) { // rising edge too early (nominally expected at 5)
+					DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
+				} else { // SOF
+					DecodeReader->state = STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF;
+				}
+			} else {
+				if (DecodeReader->posCount > 5) { // stayed low for too long
+					DecodeReaderReset(DecodeReader);
+				} else {
+					// do nothing, keep waiting
+				}
+			}
+			break;
+
+		case STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF:
+			DecodeReader->posCount++;
+			if (!bit) { // detected a falling edge
+				if (DecodeReader->posCount < 20) {         // falling edge too early (nominally expected at 21 earliest)
+					DecodeReaderReset(DecodeReader);
+				} else if (DecodeReader->posCount < 23) {  // SOF for 1 out of 4 coding
+					DecodeReader->Coding = CODING_1_OUT_OF_4;
+					DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF;
+				} else if (DecodeReader->posCount < 28) {  // falling edge too early (nominally expected at 29 latest)
+					DecodeReaderReset(DecodeReader);
+				} else {                                   // SOF for 1 out of 256 coding
+					DecodeReader->Coding = CODING_1_OUT_OF_256;
+					DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF;
+				}
+			} else {
+				if (DecodeReader->posCount > 29) { // stayed high for too long
+					DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
+				} else {
+					// do nothing, keep waiting
+				}
+			}
+			break;
+
+		case STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF:
+			DecodeReader->posCount++;
+			if (bit) { // detected rising edge
+				if (DecodeReader->Coding == CODING_1_OUT_OF_256) {
+					if (DecodeReader->posCount < 32) { // rising edge too early (nominally expected at 33)
+						DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
+					} else {
+						DecodeReader->posCount = 1;
+						DecodeReader->bitCount = 0;
+						DecodeReader->byteCount = 0;
+						DecodeReader->sum1 = 1;
+						DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256;
+						LED_B_ON();
+					}
+				} else { // CODING_1_OUT_OF_4
+					if (DecodeReader->posCount < 24) { // rising edge too early (nominally expected at 25)
+						DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
+					} else {
+						DecodeReader->posCount = 1;
+						DecodeReader->state = STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4;
+					}
+				}
+			} else {
+				if (DecodeReader->Coding == CODING_1_OUT_OF_256) {
+					if (DecodeReader->posCount > 34) { // signal stayed low for too long
+						DecodeReaderReset(DecodeReader);
+					} else {
+						// do nothing, keep waiting
+					}
+				} else { // CODING_1_OUT_OF_4
+					if (DecodeReader->posCount > 26) { // signal stayed low for too long
+						DecodeReaderReset(DecodeReader);
+					} else {
+						// do nothing, keep waiting
+					}
+				}
+			}
+			break;
+
+		case STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4:
+			DecodeReader->posCount++;
+			if (bit) {
+				if (DecodeReader->posCount == 9) {
+					DecodeReader->posCount = 1;
+					DecodeReader->bitCount = 0;
+					DecodeReader->byteCount = 0;
+					DecodeReader->sum1 = 1;
+					DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4;
+					LED_B_ON();
+				} else {
+					// do nothing, keep waiting
+				}
+			} else { // unexpected falling edge
+					DecodeReaderReset(DecodeReader);
+			}
+			break;
+
+		case STATE_READER_RECEIVE_DATA_1_OUT_OF_4:
+			DecodeReader->posCount++;
+			if (DecodeReader->posCount == 1) {
+				DecodeReader->sum1 = bit?1:0;
+			} else if (DecodeReader->posCount <= 4) {
+				if (bit) DecodeReader->sum1++;
+			} else if (DecodeReader->posCount == 5) {
+				DecodeReader->sum2 = bit?1:0;
+			} else {
+				if (bit) DecodeReader->sum2++;
+			}
+			if (DecodeReader->posCount == 8) {
+				DecodeReader->posCount = 0;
+				if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF
+					LED_B_OFF(); // Finished receiving
+					DecodeReaderReset(DecodeReader);
+					if (DecodeReader->byteCount != 0) {
+						return true;
+					}
+				} else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected a 2bit position
+					DecodeReader->shiftReg >>= 2;
+					DecodeReader->shiftReg |= (DecodeReader->bitCount << 6);
+				}
+				if (DecodeReader->bitCount == 15) { // we have a full byte
+					DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg;
+					if (DecodeReader->byteCount > DecodeReader->byteCountMax) {
+						// buffer overflow, give up
+						LED_B_OFF();
+						DecodeReaderReset(DecodeReader);
+					}
+					DecodeReader->bitCount = 0;
+					DecodeReader->shiftReg = 0;
+					if (DecodeReader->byteCount == DecodeReader->jam_search_len) {
+						if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) {
+							LED_D_ON();
+							FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM);
+							DecodeReader->state = STATE_READER_RECEIVE_JAMMING;
+						}
+					}
+				} else {
+					DecodeReader->bitCount++;
+				}
+			}
+			break;
+
+		case STATE_READER_RECEIVE_DATA_1_OUT_OF_256:
+			DecodeReader->posCount++;
+			if (DecodeReader->posCount == 1) {
+				DecodeReader->sum1 = bit?1:0;
+			} else if (DecodeReader->posCount <= 4) {
+				if (bit) DecodeReader->sum1++;
+			} else if (DecodeReader->posCount == 5) {
+				DecodeReader->sum2 = bit?1:0;
+			} else if (bit) {
+				DecodeReader->sum2++;
+			}
+			if (DecodeReader->posCount == 8) {
+				DecodeReader->posCount = 0;
+				if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF
+					LED_B_OFF(); // Finished receiving
+					DecodeReaderReset(DecodeReader);
+					if (DecodeReader->byteCount != 0) {
+						return true;
+					}
+				} else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected the bit position
+					DecodeReader->shiftReg = DecodeReader->bitCount;
+				}
+				if (DecodeReader->bitCount == 255) { // we have a full byte
+					DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg;
+					if (DecodeReader->byteCount > DecodeReader->byteCountMax) {
+						// buffer overflow, give up
+						LED_B_OFF();
+						DecodeReaderReset(DecodeReader);
+					}
+					if (DecodeReader->byteCount == DecodeReader->jam_search_len) {
+						if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) {
+							LED_D_ON();
+							FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM);
+							DecodeReader->state = STATE_READER_RECEIVE_JAMMING;
+						}
+					}
+				}
+				DecodeReader->bitCount++;
+			}
+			break;
+
+		case STATE_READER_RECEIVE_JAMMING:
+			DecodeReader->posCount++;
+			if (DecodeReader->Coding == CODING_1_OUT_OF_4) {
+				if (DecodeReader->posCount == 7*16) { // 7 bits jammed
+					FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE); // stop jamming
+					// FpgaDisableTracing();
+					LED_D_OFF();
+				} else if (DecodeReader->posCount == 8*16) {
+					DecodeReader->posCount = 0;
+					DecodeReader->output[DecodeReader->byteCount++] = 0x00;
+					DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4;
+				}
+			} else {
+				if (DecodeReader->posCount == 7*256) { // 7 bits jammend
+					FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE); // stop jamming
+					LED_D_OFF();
+				} else if (DecodeReader->posCount == 8*256) {
+					DecodeReader->posCount = 0;
+					DecodeReader->output[DecodeReader->byteCount++] = 0x00;
+					DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256;
+				}
+			}
+			break;
+
+		default:
+			LED_B_OFF();
+			DecodeReaderReset(DecodeReader);
+			break;
+	}
+
+	return false;
+}
+
+
+//-----------------------------------------------------------------------------
+// Receive a command (from the reader to us, where we are the simulated tag),
+// and store it in the given buffer, up to the given maximum length. Keeps
+// spinning, waiting for a well-framed command, until either we get one
+// (returns len) or someone presses the pushbutton on the board (returns -1).
+//
+// Assume that we're called with the SSC (to the FPGA) and ADC path set
+// correctly.
+//-----------------------------------------------------------------------------
+
+int GetIso15693CommandFromReader(uint8_t *received, size_t max_len, uint32_t *eof_time) {
+	int samples = 0;
+	bool gotFrame = false;
+	uint8_t b;
+
+	uint8_t dmaBuf[ISO15693_DMA_BUFFER_SIZE];
+
+	// the decoder data structure
+	DecodeReader_t DecodeReader = {0};
+	DecodeReaderInit(&DecodeReader, received, max_len, 0, NULL);
+
+	// wait for last transfer to complete
+	while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY));
+
+	LED_D_OFF();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
+
+	// clear receive register and wait for next transfer
+	uint32_t temp = AT91C_BASE_SSC->SSC_RHR;
+	(void) temp;
+	while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)) ;
+
+	uint32_t dma_start_time = GetCountSspClk() & 0xfffffff8;
+
+	// Setup and start DMA.
+	FpgaSetupSscDma(dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+	uint8_t *upTo = dmaBuf;
+
+	for (;;) {
+		uint16_t behindBy = ((uint8_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1);
+
+		if (behindBy == 0) continue;
+
+		b = *upTo++;
+		if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {               // we have read all of the DMA buffer content.
+			upTo = dmaBuf;                                             // start reading the circular buffer from the beginning
+			if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+				Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
+				break;
+			}
+		}
+		if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) {              // DMA Counter Register had reached 0, already rotated.
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;          // refresh the DMA Next Buffer and
+			AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE;   // DMA Next Counter registers
+		}
+
+		for (int i = 7; i >= 0; i--) {
+			if (Handle15693SampleFromReader((b >> i) & 0x01, &DecodeReader)) {
+				*eof_time = dma_start_time + samples - DELAY_READER_TO_ARM; // end of EOF
+				gotFrame = true;
+				break;
+			}
+			samples++;
+		}
+
+		if (gotFrame) {
+			break;
+		}
+
+		if (BUTTON_PRESS()) {
+			DecodeReader.byteCount = -1;
+			break;
+		}
+
+		WDT_HIT();
+	}
+
+	FpgaDisableSscDma();
+
+	if (DEBUG) Dbprintf("samples = %d, gotFrame = %d, Decoder: state = %d, len = %d, bitCount = %d, posCount = %d",
+						samples, gotFrame, DecodeReader.state, DecodeReader.byteCount, DecodeReader.bitCount, DecodeReader.posCount);
+
+	if (DecodeReader.byteCount > 0) {
+		uint32_t sof_time = *eof_time
+						- DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128:2048) // time for byte transfers
+						- 32  // time for SOF transfer
+						- 16; // time for EOF transfer
+		LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*32, *eof_time*32, NULL, true);
+	}
+
+	return DecodeReader.byteCount;
+}
+
+
+// Construct an identify (Inventory) request, which is the first
+// thing that you must send to a tag to get a response.
+static void BuildIdentifyRequest(uint8_t *cmd) {
+	uint16_t crc;
+	// one sub-carrier, inventory, 1 slot, fast rate
+	cmd[0] = ISO15693_REQ_INVENTORY | ISO15693_REQINV_SLOT1 | ISO15693_REQ_DATARATE_HIGH;
+	// inventory command code
+	cmd[1] = 0x01;
+	// no mask
+	cmd[2] = 0x00;
+	//Now the CRC
+	crc = Iso15693Crc(cmd, 3);
+	cmd[3] = crc & 0xff;
+	cmd[4] = crc >> 8;
+}
+
+
+//-----------------------------------------------------------------------------
+// Start to read an ISO 15693 tag. We send an identify request, then wait
+// for the response. The response is not demodulated, just left in the buffer
+// so that it can be downloaded to a PC and processed there.
+//-----------------------------------------------------------------------------
+void AcquireRawAdcSamplesIso15693(void) {
+	LED_A_ON();
+
+	uint8_t *dest = BigBuf_get_addr();
+
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER);
+	LED_D_ON();
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+	uint8_t cmd[5];
+	BuildIdentifyRequest(cmd);
+	CodeIso15693AsReader(cmd, sizeof(cmd));
+
+	// Give the tags time to energize
+	SpinDelay(100);
+
+	// Now send the command
+	uint32_t start_time = 0;
+	TransmitTo15693Tag(ToSend, ToSendMax, &start_time);
+
+	// wait for last transfer to complete
+	while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)) ;
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE);
+
+	for(int c = 0; c < 4000; ) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+			uint16_t r = AT91C_BASE_SSC->SSC_RHR;
+			dest[c++] = r >> 5;
+		}
+	}
 
-// Modified by Greg Jones, Jan 2009 to perform modulation onboard in arm rather than on PC
-// Also added additional reader commands (SELECT, READ etc.)
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LEDsoff();
+}
 
-//-----------------------------------------------------------------------------
-#include "proxmark3.h"
-#include "util.h"
-#include "apps.h"
-#include "string.h"
 
-// FROM winsrc\prox.h //////////////////////////////////
-#define arraylen(x) (sizeof(x)/sizeof((x)[0]))
+void SnoopIso15693(uint8_t jam_search_len, uint8_t *jam_search_string) {
 
-//-----------------------------------------------------------------------------
-// Map a sequence of octets (~layer 2 command) into the set of bits to feed
-// to the FPGA, to transmit that command to the tag.
-//-----------------------------------------------------------------------------
+	LED_A_ON();
 
-	// The sampling rate is 106.353 ksps/s, for T = 18.8 us
-
-	// SOF defined as
-	// 1) Unmodulated time of 56.64us
-	// 2) 24 pulses of 423.75khz
-	// 3) logic '1' (unmodulated for 18.88us followed by 8 pulses of 423.75khz)
-
-	static const int FrameSOF[] = {
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-		 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-		-1, -1, -1, -1,
-		-1, -1, -1, -1,
-		 1,  1,  1,  1,
-		 1,  1,  1,  1
-	};
-	static const int Logic0[] = {
-		 1,  1,  1,  1,
-		 1,  1,  1,  1,
-		-1, -1, -1, -1,
-		-1, -1, -1, -1
-	};
-	static const int Logic1[] = {
-		-1, -1, -1, -1,
-		-1, -1, -1, -1,
-		 1,  1,  1,  1,
-		 1,  1,  1,  1
-	};
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
-	// EOF defined as
-	// 1) logic '0' (8 pulses of 423.75khz followed by unmodulated for 18.88us)
-	// 2) 24 pulses of 423.75khz
-	// 3) Unmodulated time of 56.64us
-
-	static const int FrameEOF[] = {
-		 1,  1,  1,  1,
-		 1,  1,  1,  1,
-		-1, -1, -1, -1,
-		-1, -1, -1, -1,
-		 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-		 1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
-	};
+	clear_trace();
+	set_tracing(true);
 
-static void CodeIso15693AsReader(uint8_t *cmd, int n)
-{
-	int i, j;
+	// The DMA buffer, used to stream samples from the FPGA
+	uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE];
 
-	ToSendReset();
+	// Count of samples received so far, so that we can include timing
+	// information in the trace buffer.
+	int samples = 0;
 
-	// Give it a bit of slack at the beginning
-	for(i = 0; i < 24; i++) {
-		ToSendStuffBit(1);
+	DecodeTag_t DecodeTag = {0};
+	uint8_t response[ISO15693_MAX_RESPONSE_LENGTH];
+	DecodeTagInit(&DecodeTag, response, sizeof(response));
+
+	DecodeReader_t DecodeReader = {0};
+	uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH];
+	DecodeReaderInit(&DecodeReader, cmd, sizeof(cmd), jam_search_len, jam_search_string);
+
+	// Print some debug information about the buffer sizes
+	if (DEBUG) {
+		Dbprintf("Snooping buffers initialized:");
+		Dbprintf("  Trace:         %i bytes", BigBuf_max_traceLen());
+		Dbprintf("  Reader -> tag: %i bytes", ISO15693_MAX_COMMAND_LENGTH);
+		Dbprintf("  tag -> Reader: %i bytes", ISO15693_MAX_RESPONSE_LENGTH);
+		Dbprintf("  DMA:           %i bytes", ISO15693_DMA_BUFFER_SIZE * sizeof(uint16_t));
 	}
+	Dbprintf("Snoop started. Press PM3 Button to stop.");
 
-	ToSendStuffBit(0);
-	ToSendStuffBit(1);
-	ToSendStuffBit(1);
-	ToSendStuffBit(1);
-	ToSendStuffBit(1);
-	ToSendStuffBit(0);
-	ToSendStuffBit(1);
-	ToSendStuffBit(1);
-	for(i = 0; i < n; i++) {
-		for(j = 0; j < 8; j += 2) {
-			int these = (cmd[i] >> j) & 3;
-			switch(these) {
-				case 0:
-					ToSendStuffBit(1);
-					ToSendStuffBit(0);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					break;
-				case 1:
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(0);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					break;
-				case 2:
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(0);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					break;
-				case 3:
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(1);
-					ToSendStuffBit(0);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE);
+	LED_D_OFF();
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
+	StartCountSspClk();
+	FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+
+	bool TagIsActive = false;
+	bool ReaderIsActive = false;
+	bool ExpectTagAnswer = false;
+	uint32_t dma_start_time = 0;
+	uint16_t *upTo = dmaBuf;
+
+	uint16_t max_behindBy = 0;
+	
+	// And now we loop, receiving samples.
+	for(;;) {
+		uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1);
+		if (behindBy > max_behindBy) {
+			max_behindBy = behindBy;
+		}
+		
+		if (behindBy == 0) continue;
+
+		samples++;
+		if (samples == 1) {
+			// DMA has transferred the very first data
+			dma_start_time = GetCountSspClk() & 0xfffffff0;
+		}
+
+		uint16_t snoopdata = *upTo++;
+
+		if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {                   // we have read all of the DMA buffer content.
+			upTo = dmaBuf;                                                 // start reading the circular buffer from the beginning
+			if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+				// FpgaDisableTracing();
+				Dbprintf("About to blow circular buffer - aborted! behindBy=%d, samples=%d", behindBy, samples);
+				break;
+			}
+			if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) {              // DMA Counter Register had reached 0, already rotated.
+				AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;          // refresh the DMA Next Buffer and
+				AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE;   // DMA Next Counter registers
+				WDT_HIT();
+				if (BUTTON_PRESS()) {
+					DbpString("Snoop stopped.");
 					break;
+				}
 			}
 		}
-	}
-	ToSendStuffBit(1);
-	ToSendStuffBit(1);
-	ToSendStuffBit(0);
-	ToSendStuffBit(1);
-
-	// And slack at the end, too.
-	for(i = 0; i < 24; i++) {
-		ToSendStuffBit(1);
-	}
-}
 
-//-----------------------------------------------------------------------------
-// The CRC used by ISO 15693.
-//-----------------------------------------------------------------------------
-static uint16_t Crc(uint8_t *v, int n)
-{
-	uint32_t reg;
-	int i, j;
-
-	reg = 0xffff;
-	for(i = 0; i < n; i++) {
-		reg = reg ^ ((uint32_t)v[i]);
-		for (j = 0; j < 8; j++) {
-			if (reg & 0x0001) {
-				reg = (reg >> 1) ^ 0x8408;
+		if (!TagIsActive) {                                                // no need to try decoding reader data if the tag is sending
+			if (Handle15693SampleFromReader(snoopdata & 0x02, &DecodeReader)) {
+				// FpgaDisableSscDma();
+				uint32_t eof_time = dma_start_time + samples*16 + 8 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+				if (DecodeReader.byteCount > 0) {
+					uint32_t sof_time = eof_time
+									- DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+									- 32*16  // time for SOF transfer
+									- 16*16; // time for EOF transfer
+					LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+				}
+				/* And ready to receive another command. */
+				DecodeReaderReset(&DecodeReader);
+				/* And also reset the demod code, which might have been */
+				/* false-triggered by the commands from the reader. */
+				DecodeTagReset(&DecodeTag);
+				ReaderIsActive = false;
+				ExpectTagAnswer = true;
+				// upTo = dmaBuf;
+				// samples = 0;
+				// FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+				// continue;
+			} else if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) {
+				// FpgaDisableSscDma();
+				uint32_t eof_time = dma_start_time + samples*16 + 16 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+				if (DecodeReader.byteCount > 0) {
+					uint32_t sof_time = eof_time
+									- DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+									- 32*16  // time for SOF transfer
+									- 16*16; // time for EOF transfer
+					LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+				}
+				/* And ready to receive another command. */
+				DecodeReaderReset(&DecodeReader);
+				/* And also reset the demod code, which might have been */
+				/* false-triggered by the commands from the reader. */
+				DecodeTagReset(&DecodeTag);
+				ReaderIsActive = false;
+				ExpectTagAnswer = true;
+				// upTo = dmaBuf;
+				// samples = 0;
+				// FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+				// continue;
 			} else {
-				reg = (reg >> 1);
+				ReaderIsActive = (DecodeReader.state >= STATE_READER_RECEIVE_DATA_1_OUT_OF_4);
 			}
 		}
-	}
-
-	return ~reg;
-}
 
-char *strcat(char *dest, const char *src)
-{
-	size_t dest_len = strlen(dest);
-	size_t i;
+		if (!ReaderIsActive && ExpectTagAnswer) {                       // no need to try decoding tag data if the reader is currently sending or no answer expected yet
+			if (Handle15693SamplesFromTag(snoopdata >> 2, &DecodeTag)) {
+				// FpgaDisableSscDma();
+				uint32_t eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM_SNOOP; // end of EOF
+				if (DecodeTag.lastBit == SOF_PART2) {
+					eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS)
+				}
+				uint32_t sof_time = eof_time
+									- DecodeTag.len * 8 * 8 * 16 // time for byte transfers
+									- 32 * 16  // time for SOF transfer
+									- (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer
+				LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, eof_time*4, NULL, false);
+				// And ready to receive another response.
+				DecodeTagReset(&DecodeTag);
+				DecodeReaderReset(&DecodeReader);
+				ExpectTagAnswer = false;
+				TagIsActive = false;
+				// upTo = dmaBuf;
+				// samples = 0;
+				// FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+				// continue;
+			} else {
+				TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
+			}
+		}
 
-	for (i = 0 ; src[i] != '\0' ; i++)
-	        dest[dest_len + i] = src[i];
-	dest[dest_len + i] = '\0';
+	}
 
-	return dest;
+	FpgaDisableSscDma();
+
+	DbpString("Snoop statistics:");
+	Dbprintf("  ExpectTagAnswer: %d, TagIsActive: %d, ReaderIsActive: %d", ExpectTagAnswer, TagIsActive, ReaderIsActive);
+	Dbprintf("  DecodeTag State: %d", DecodeTag.state);
+	Dbprintf("  DecodeTag byteCnt: %d", DecodeTag.len);
+	Dbprintf("  DecodeTag posCount: %d", DecodeTag.posCount);
+	Dbprintf("  DecodeReader State: %d", DecodeReader.state);
+	Dbprintf("  DecodeReader byteCnt: %d", DecodeReader.byteCount);
+	Dbprintf("  DecodeReader posCount: %d", DecodeReader.posCount);
+	Dbprintf("  Trace length: %d", BigBuf_get_traceLen());
+	Dbprintf("  Max behindBy: %d", max_behindBy);
 }
 
-////////////////////////////////////////// code to do 'itoa'
 
-/* reverse:  reverse string s in place */
-void reverse(char s[])
-{
-    int c, i, j;
+// Initialize the proxmark as iso15k reader
+void Iso15693InitReader(void) {
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
-    for (i = 0, j = strlen(s)-1; i<j; i++, j--) {
-        c = s[i];
-        s[i] = s[j];
-        s[j] = c;
-    }
-}
+	// switch field off and wait until tag resets
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+	SpinDelay(10);
+
+	// switch field on
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER);
+	LED_D_ON();
+	
+	// initialize SSC and select proper AD input
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-/* itoa:  convert n to characters in s */
-void itoa(int n, char s[])
-{
-    int i, sign;
-
-    if ((sign = n) < 0)  /* record sign */
-        n = -n;          /* make n positive */
-    i = 0;
-    do {       /* generate digits in reverse order */
-        s[i++] = n % 10 + '0';   /* get next digit */
-    } while ((n /= 10) > 0);     /* delete it */
-    if (sign < 0)
-        s[i++] = '-';
-    s[i] = '\0';
-    reverse(s);
+	// give tags some time to energize
+	SpinDelay(250);
 }
 
-//////////////////////////////////////// END 'itoa' CODE
+///////////////////////////////////////////////////////////////////////
+// ISO 15693 Part 3 - Air Interface
+// This section basically contains transmission and receiving of bits
+///////////////////////////////////////////////////////////////////////
 
-//-----------------------------------------------------------------------------
-// Encode (into the ToSend buffers) an identify request, which is the first
-// thing that you must send to a tag to get a response.
-//-----------------------------------------------------------------------------
-static void BuildIdentifyRequest(void)
-{
-	uint8_t cmd[5];
 
+// uid is in transmission order (which is reverse of display order)
+static void BuildReadBlockRequest(uint8_t *uid, uint8_t blockNumber, uint8_t *cmd) {
 	uint16_t crc;
-	// one sub-carrier, inventory, 1 slot, fast rate
-	// AFI is at bit 5 (1<<4) when doing an INVENTORY
-	cmd[0] = (1 << 2) | (1 << 5) | (1 << 1);
-	// inventory command code
-	cmd[1] = 0x01;
-	// no mask
-	cmd[2] = 0x00;
+	// If we set the Option_Flag in this request, the VICC will respond with the security status of the block
+	// followed by the block data
+	cmd[0] = ISO15693_REQ_OPTION | ISO15693_REQ_ADDRESS | ISO15693_REQ_DATARATE_HIGH;
+	// READ BLOCK command code
+	cmd[1] = ISO15693_READBLOCK;
+	// UID may be optionally specified here
+	// 64-bit UID
+	cmd[2] = uid[0];
+	cmd[3] = uid[1];
+	cmd[4] = uid[2];
+	cmd[5] = uid[3];
+	cmd[6] = uid[4];
+	cmd[7] = uid[5];
+	cmd[8] = uid[6];
+	cmd[9] = uid[7]; // 0xe0; // always e0 (not exactly unique)
+	// Block number to read
+	cmd[10] = blockNumber;
 	//Now the CRC
-	crc = Crc(cmd, 3);
-	cmd[3] = crc & 0xff;
-	cmd[4] = crc >> 8;
+	crc = Iso15693Crc(cmd, 11); // the crc needs to be calculated over 11 bytes
+	cmd[11] = crc & 0xff;
+	cmd[12] = crc >> 8;
 
-	CodeIso15693AsReader(cmd, sizeof(cmd));
 }
 
-static void __attribute__((unused)) BuildSysInfoRequest(uint8_t *uid)
-{
+
+// Now the VICC>VCD responses when we are simulating a tag
+static void BuildInventoryResponse(uint8_t *uid) {
 	uint8_t cmd[12];
 
 	uint16_t crc;
-	// If we set the Option_Flag in this request, the VICC will respond with the secuirty status of the block
-	// followed by teh block data
-	// one sub-carrier, inventory, 1 slot, fast rate
-	cmd[0] =  (1 << 5) | (1 << 1); // no SELECT bit
-	// System Information command code
-	cmd[1] = 0x2B;
-	// UID may be optionally specified here
+
+	cmd[0] = 0; // No error, no protocol format extension
+	cmd[1] = 0; // DSFID (data storage format identifier).  0x00 = not supported
 	// 64-bit UID
-	cmd[2] = 0x32;
-	cmd[3]= 0x4b;
-	cmd[4] = 0x03;
-	cmd[5] = 0x01;
-	cmd[6] = 0x00;
-	cmd[7] = 0x10;
-	cmd[8] = 0x05;
-	cmd[9]= 0xe0; // always e0 (not exactly unique)
+	cmd[2] = uid[7]; //0x32;
+	cmd[3] = uid[6]; //0x4b;
+	cmd[4] = uid[5]; //0x03;
+	cmd[5] = uid[4]; //0x01;
+	cmd[6] = uid[3]; //0x00;
+	cmd[7] = uid[2]; //0x10;
+	cmd[8] = uid[1]; //0x05;
+	cmd[9] = uid[0]; //0xe0;
 	//Now the CRC
-	crc = Crc(cmd, 10); // the crc needs to be calculated over 2 bytes
+	crc = Iso15693Crc(cmd, 10);
 	cmd[10] = crc & 0xff;
 	cmd[11] = crc >> 8;
 
-	CodeIso15693AsReader(cmd, sizeof(cmd));
+	CodeIso15693AsTag(cmd, sizeof(cmd));
 }
 
-static void BuildSelectRequest( uint8_t uid[])
-{
+// Universal Method for sending to and recv bytes from a tag
+//  init ... should we initialize the reader?
+//  speed ... 0 low speed, 1 hi speed
+//  *recv will contain the tag's answer
+//  return: length of received data, or -1 for timeout
+int SendDataTag(uint8_t *send, int sendlen, bool init, bool speed_fast, uint8_t *recv, uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) {
 
-//	uid[6]=0x31;  // this is getting ignored - the uid array is not happening...
-	uint8_t cmd[12];
+	if (init) {
+		Iso15693InitReader();
+		StartCountSspClk();
+	}
+
+	int answerLen = 0;
+
+	if (speed_fast) {
+		// high speed (1 out of 4)
+		CodeIso15693AsReader(send, sendlen);
+	} else {
+		// low speed (1 out of 256)
+		CodeIso15693AsReader256(send, sendlen);
+	}
+
+	TransmitTo15693Tag(ToSend, ToSendMax, &start_time);
+	uint32_t end_time = start_time + 32*(8*ToSendMax-4); // substract the 4 padding bits after EOF
+	LogTrace_ISO15693(send, sendlen, start_time*4, end_time*4, NULL, true);
+
+	// Now wait for a response
+	if (recv != NULL) {
+		answerLen = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time);
+	}
+
+	return answerLen;
+}
+
+
+int SendDataTagEOF(uint8_t *recv, uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) {
+
+	int answerLen = 0;
+
+	CodeIso15693AsReaderEOF();
 
+	TransmitTo15693Tag(ToSend, ToSendMax, &start_time);
+	uint32_t end_time = start_time + 32*(8*ToSendMax-4); // substract the 4 padding bits after EOF
+	LogTrace_ISO15693(NULL, 0, start_time*4, end_time*4, NULL, true);
+
+	// Now wait for a response
+	if (recv != NULL) {
+		answerLen = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time);
+	}
+
+	return answerLen;
+}
+
+
+// --------------------------------------------------------------------
+// Debug Functions
+// --------------------------------------------------------------------
+
+// Decodes a message from a tag and displays its metadata and content
+#define DBD15STATLEN 48
+void DbdecodeIso15693Answer(int len, uint8_t *d) {
+	char status[DBD15STATLEN+1]={0};
 	uint16_t crc;
-	// one sub-carrier, inventory, 1 slot, fast rate
-	//cmd[0] = (1 << 2) | (1 << 5) | (1 << 1);	// INVENTROY FLAGS
-	cmd[0] = (1 << 4) | (1 << 5) | (1 << 1);	// Select and addressed FLAGS
-	// SELECT command code
-	cmd[1] = 0x25;
-	// 64-bit UID
-//	cmd[2] = uid[0];//0x32;
-//	cmd[3]= uid[1];//0x4b;
-//	cmd[4] = uid[2];//0x03;
-//	cmd[5] = uid[3];//0x01;
-//	cmd[6] = uid[4];//0x00;
-//	cmd[7] = uid[5];//0x10;
-//	cmd[8] = uid[6];//0x05;
-	cmd[2] = 0x32;//
-	cmd[3] = 0x4b;
-	cmd[4] = 0x03;
-	cmd[5] = 0x01;
-	cmd[6] = 0x00;
-	cmd[7] = 0x10;
-	cmd[8] = 0x05; // infineon?
 
-	cmd[9]= 0xe0; // always e0 (not exactly unique)
+	if (len > 3) {
+		if (d[0] & ISO15693_RES_EXT)
+			strncat(status,"ProtExt ", DBD15STATLEN);
+		if (d[0] & ISO15693_RES_ERROR) {
+			// error
+			strncat(status,"Error ", DBD15STATLEN);
+			switch (d[1]) {
+				case 0x01:
+					strncat(status,"01:notSupp", DBD15STATLEN);
+					break;
+				case 0x02:
+					strncat(status,"02:notRecog", DBD15STATLEN);
+					break;
+				case 0x03:
+					strncat(status,"03:optNotSupp", DBD15STATLEN);
+					break;
+				case 0x0f:
+					strncat(status,"0f:noInfo", DBD15STATLEN);
+					break;
+				case 0x10:
+					strncat(status,"10:doesn'tExist", DBD15STATLEN);
+					break;
+				case 0x11:
+					strncat(status,"11:lockAgain", DBD15STATLEN);
+					break;
+				case 0x12:
+					strncat(status,"12:locked", DBD15STATLEN);
+					break;
+				case 0x13:
+					strncat(status,"13:progErr", DBD15STATLEN);
+					break;
+				case 0x14:
+					strncat(status,"14:lockErr", DBD15STATLEN);
+					break;
+				default:
+					strncat(status,"unknownErr", DBD15STATLEN);
+			}
+			strncat(status," ", DBD15STATLEN);
+		} else {
+			strncat(status,"NoErr ", DBD15STATLEN);
+		}
 
-//	DbpIntegers(cmd[8],cmd[7],cmd[6]);
-	// Now the CRC
-	crc = Crc(cmd, 10); // the crc needs to be calculated over 10 bytes
-	cmd[10] = crc & 0xff;
-	cmd[11] = crc >> 8;
+		crc=Iso15693Crc(d,len-2);
+		if ( (( crc & 0xff ) == d[len-2]) && (( crc >> 8 ) == d[len-1]) )
+			strncat(status,"CrcOK",DBD15STATLEN);
+		else
+			strncat(status,"CrcFail!",DBD15STATLEN);
 
-	CodeIso15693AsReader(cmd, sizeof(cmd));
+		Dbprintf("%s",status);
+	}
+}
+
+
+
+///////////////////////////////////////////////////////////////////////
+// Functions called via USB/Client
+///////////////////////////////////////////////////////////////////////
+
+void SetDebugIso15693(uint32_t debug) {
+	DEBUG=debug;
+	Dbprintf("Iso15693 Debug is now %s",DEBUG?"on":"off");
+	return;
+}
+
+
+//---------------------------------------------------------------------------------------
+// Simulate an ISO15693 reader, perform anti-collision and then attempt to read a sector.
+// all demodulation performed in arm rather than host. - greg
+//---------------------------------------------------------------------------------------
+void ReaderIso15693(uint32_t parameter) {
+
+	LED_A_ON();
+
+	set_tracing(true);
+
+	uint8_t TagUID[8] = {0x00};
+	uint8_t answer[ISO15693_MAX_RESPONSE_LENGTH];
+
+	// FIRST WE RUN AN INVENTORY TO GET THE TAG UID
+	// THIS MEANS WE CAN PRE-BUILD REQUESTS TO SAVE CPU TIME
+
+	// Now send the IDENTIFY command
+	uint8_t cmd[5];
+	BuildIdentifyRequest(cmd);
+	uint32_t start_time = 0;
+	uint32_t eof_time;
+	int answerLen = SendDataTag(cmd, sizeof(cmd), true, true, answer, sizeof(answer), start_time, ISO15693_READER_TIMEOUT, &eof_time);
+	start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
+
+	if (answerLen >= 12) { // we should do a better check than this
+		TagUID[0] = answer[2];
+		TagUID[1] = answer[3];
+		TagUID[2] = answer[4];
+		TagUID[3] = answer[5];
+		TagUID[4] = answer[6];
+		TagUID[5] = answer[7];
+		TagUID[6] = answer[8]; // IC Manufacturer code
+		TagUID[7] = answer[9]; // always E0
+	}
+
+	Dbprintf("%d octets read from IDENTIFY request:", answerLen);
+	DbdecodeIso15693Answer(answerLen, answer);
+	Dbhexdump(answerLen, answer, false);
+
+	// UID is reverse
+	if (answerLen >= 12)
+		Dbprintf("UID = %02hX%02hX%02hX%02hX%02hX%02hX%02hX%02hX",
+			TagUID[7],TagUID[6],TagUID[5],TagUID[4],
+			TagUID[3],TagUID[2],TagUID[1],TagUID[0]);
+
+	// read all pages
+	if (answerLen >= 12 && DEBUG) {
+		for (int i = 0; i < 32; i++) {  // sanity check, assume max 32 pages
+			uint8_t cmd[13];
+			BuildReadBlockRequest(TagUID, i, cmd);
+			answerLen = SendDataTag(cmd, sizeof(cmd), false, true, answer, sizeof(answer), start_time, ISO15693_READER_TIMEOUT, &eof_time);
+			start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
+			if (answerLen > 0) {
+				Dbprintf("READ SINGLE BLOCK %d returned %d octets:", i, answerLen);
+				DbdecodeIso15693Answer(answerLen, answer);
+				Dbhexdump(answerLen, answer, false);
+				if ( *((uint32_t*) answer) == 0x07160101 ) break; // exit on NoPageErr
+			}
+		}
+	}
+
+	// for the time being, switch field off to protect RDV4
+	// note: this prevents using hf 15 cmd with s option - which isn't implemented yet anyway
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+
+	LED_A_OFF();
+}
+
+
+// Initialize the proxmark as iso15k tag
+void Iso15693InitTag(void) {
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
+	LED_D_OFF();
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR);
+	StartCountSspClk();
+}
+
+
+// Simulate an ISO15693 TAG.
+// For Inventory command: print command and send Inventory Response with given UID
+// TODO: interpret other reader commands and send appropriate response
+void SimTagIso15693(uint32_t parameter, uint8_t *uid) {
+
+	LED_A_ON();
+
+	Iso15693InitTag();
+
+	// Build a suitable response to the reader INVENTORY command
+	BuildInventoryResponse(uid);
+
+	// Listen to reader
+	while (!BUTTON_PRESS()) {
+		uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH];
+		uint32_t eof_time = 0, start_time = 0;
+		int cmd_len = GetIso15693CommandFromReader(cmd, sizeof(cmd), &eof_time);
+
+		if ((cmd_len >= 5) && (cmd[0] & ISO15693_REQ_INVENTORY) && (cmd[1] == ISO15693_INVENTORY)) { // TODO: check more flags
+			bool slow = !(cmd[0] & ISO15693_REQ_DATARATE_HIGH);
+			start_time = eof_time + DELAY_ISO15693_VCD_TO_VICC_SIM;
+			TransmitTo15693Reader(ToSend, ToSendMax, &start_time, 0, slow);
+		}
+
+		Dbprintf("%d bytes read from reader:", cmd_len);
+		Dbhexdump(cmd_len, cmd, false);
+	}
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+	LED_A_OFF();
+}
+
+
+// Since there is no standardized way of reading the AFI out of a tag, we will brute force it
+// (some manufactures offer a way to read the AFI, though)
+void BruteforceIso15693Afi(uint32_t speed) {
+	LED_A_ON();
+
+	uint8_t data[6];
+	uint8_t recv[ISO15693_MAX_RESPONSE_LENGTH];
+	int datalen = 0, recvlen = 0;
+	uint32_t eof_time;
+
+	// first without AFI
+	// Tags should respond without AFI and with AFI=0 even when AFI is active
+
+	data[0] = ISO15693_REQ_DATARATE_HIGH | ISO15693_REQ_INVENTORY | ISO15693_REQINV_SLOT1;
+	data[1] = ISO15693_INVENTORY;
+	data[2] = 0; // mask length
+	datalen = Iso15693AddCrc(data,3);
+	uint32_t start_time = GetCountSspClk();
+	recvlen = SendDataTag(data, datalen, true, speed, recv, sizeof(recv), 0, ISO15693_READER_TIMEOUT, &eof_time);
+	start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
+	WDT_HIT();
+	if (recvlen>=12) {
+		Dbprintf("NoAFI UID=%s", Iso15693sprintUID(NULL, &recv[2]));
+	}
+
+	// now with AFI
+
+	data[0] = ISO15693_REQ_DATARATE_HIGH | ISO15693_REQ_INVENTORY | ISO15693_REQINV_AFI | ISO15693_REQINV_SLOT1;
+	data[1] = ISO15693_INVENTORY;
+	data[2] = 0; // AFI
+	data[3] = 0; // mask length
+
+	for (int i = 0; i < 256; i++) {
+		data[2] = i & 0xFF;
+		datalen = Iso15693AddCrc(data,4);
+		recvlen = SendDataTag(data, datalen, false, speed, recv, sizeof(recv), start_time, ISO15693_READER_TIMEOUT, &eof_time);
+		start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
+		WDT_HIT();
+		if (recvlen >= 12) {
+			Dbprintf("AFI=%i UID=%s", i, Iso15693sprintUID(NULL, &recv[2]));
+		}
+	}
+	Dbprintf("AFI Bruteforcing done.");
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+	LED_A_OFF();
+
+}
+
+// Allows to directly send commands to the tag via the client
+void DirectTag15693Command(uint32_t datalen, uint32_t speed, uint32_t recv, uint8_t data[]) {
+
+	LED_A_ON();
+
+	int recvlen = 0;
+	uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH];
+	uint32_t eof_time;
+
+	uint16_t timeout;
+    bool request_answer = false;
+	
+	switch (data[1]) {
+		case ISO15693_WRITEBLOCK:
+		case ISO15693_LOCKBLOCK:
+		case ISO15693_WRITE_MULTI_BLOCK:
+		case ISO15693_WRITE_AFI:
+		case ISO15693_LOCK_AFI:
+		case ISO15693_WRITE_DSFID:
+		case ISO15693_LOCK_DSFID:
+			timeout = ISO15693_READER_TIMEOUT_WRITE;
+			request_answer = data[0] & ISO15693_REQ_OPTION;
+			break;
+		default:
+			timeout = ISO15693_READER_TIMEOUT;
+	}		
+
+	if (DEBUG) {
+		Dbprintf("SEND:");
+		Dbhexdump(datalen, data, false);
+	}
+
+	recvlen = SendDataTag(data, datalen, true, speed, (recv?recvbuf:NULL), sizeof(recvbuf), 0, timeout, &eof_time);
+
+	if (request_answer) { // send a single EOF to get the tag response
+		recvlen = SendDataTagEOF((recv?recvbuf:NULL), sizeof(recvbuf), 0, ISO15693_READER_TIMEOUT, &eof_time);
+	}
+	
+	// for the time being, switch field off to protect rdv4.0
+	// note: this prevents using hf 15 cmd with s option - which isn't implemented yet anyway
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+
+	if (recv) {
+		if (DEBUG) {
+			Dbprintf("RECV:");
+			if (recvlen > 0) {
+				Dbhexdump(recvlen, recvbuf, false);
+				DbdecodeIso15693Answer(recvlen, recvbuf);
+			}
+		}
+		if (recvlen > ISO15693_MAX_RESPONSE_LENGTH) {
+			recvlen = ISO15693_MAX_RESPONSE_LENGTH;
+		}
+		cmd_send(CMD_ACK, recvlen, 0, 0, recvbuf, ISO15693_MAX_RESPONSE_LENGTH);
+	}
+
+	LED_A_OFF();
+}
+
+//-----------------------------------------------------------------------------
+// Work with "magic Chinese" card.
+//
+//-----------------------------------------------------------------------------
+
+// Set the UID on Magic ISO15693 tag (based on Iceman's LUA-script).
+void SetTag15693Uid(uint8_t *uid) {
+
+	LED_A_ON();
+
+	uint8_t cmd[4][9] = {
+		{ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x3e, 0x00, 0x00, 0x00, 0x00},
+		{ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x3f, 0x69, 0x96, 0x00, 0x00},
+		{ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x38},
+		{ISO15693_REQ_DATARATE_HIGH, ISO15693_WRITEBLOCK, 0x39}
+	};
+
+	uint16_t crc;
+
+	int recvlen = 0;
+	uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH];
+	uint32_t eof_time;
+
+	// Command 3 : 022138u8u7u6u5 (where uX = uid byte X)
+	cmd[2][3] = uid[7];
+	cmd[2][4] = uid[6];
+	cmd[2][5] = uid[5];
+	cmd[2][6] = uid[4];
+
+	// Command 4 : 022139u4u3u2u1 (where uX = uid byte X)
+	cmd[3][3] = uid[3];
+	cmd[3][4] = uid[2];
+	cmd[3][5] = uid[1];
+	cmd[3][6] = uid[0];
+
+	uint32_t start_time = 0;
+	
+	for (int i = 0; i < 4; i++) {
+		// Add the CRC
+		crc = Iso15693Crc(cmd[i], 7);
+		cmd[i][7] = crc & 0xff;
+		cmd[i][8] = crc >> 8;
+
+		recvlen = SendDataTag(cmd[i], sizeof(cmd[i]), i==0?true:false, true, recvbuf, sizeof(recvbuf), start_time, ISO15693_READER_TIMEOUT_WRITE, &eof_time);
+		start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
+		if (DEBUG) {
+			Dbprintf("SEND:");
+			Dbhexdump(sizeof(cmd[i]), cmd[i], false);
+			Dbprintf("RECV:");
+			if (recvlen > 0) {
+				Dbhexdump(recvlen, recvbuf, false);
+				DbdecodeIso15693Answer(recvlen, recvbuf);
+			}
+		}
+		// Note: need to know if we expect an answer from one of the magic commands
+		// if (recvlen < 0) {
+			// break;
+		// }
+	}
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+
+	cmd_send(CMD_ACK, recvlen, 0, 0, recvbuf, recvlen);
+	LED_A_OFF();
 }
 
-static void __attribute__((unused)) BuildReadBlockRequest(uint8_t *uid, uint8_t blockNumber )
+
+
+// --------------------------------------------------------------------
+// -- Misc & deprecated functions
+// --------------------------------------------------------------------
+
+/*
+
+// do not use; has a fix UID
+static void __attribute__((unused)) BuildSysInfoRequest(uint8_t *uid)
 {
-	uint8_t cmd[13];
+	uint8_t cmd[12];
 
 	uint16_t crc;
-	// If we set the Option_Flag in this request, the VICC will respond with the secuirty status of the block
-	// followed by teh block data
+	// If we set the Option_Flag in this request, the VICC will respond with the security status of the block
+	// followed by the block data
 	// one sub-carrier, inventory, 1 slot, fast rate
-	cmd[0] = (1 << 6)| (1 << 5) | (1 << 1); // no SELECT bit
-	// READ BLOCK command code
-	cmd[1] = 0x20;
+	cmd[0] =  (1 << 5) | (1 << 1); // no SELECT bit
+	// System Information command code
+	cmd[1] = 0x2B;
 	// UID may be optionally specified here
 	// 64-bit UID
 	cmd[2] = 0x32;
@@ -325,23 +1885,23 @@ static void __attribute__((unused)) BuildReadBlockRequest(uint8_t *uid, uint8_t
 	cmd[7] = 0x10;
 	cmd[8] = 0x05;
 	cmd[9]= 0xe0; // always e0 (not exactly unique)
-	// Block number to read
-	cmd[10] = blockNumber;//0x00;
 	//Now the CRC
-	crc = Crc(cmd, 11); // the crc needs to be calculated over 2 bytes
-	cmd[11] = crc & 0xff;
-	cmd[12] = crc >> 8;
+	crc = Iso15693Crc(cmd, 10); // the crc needs to be calculated over 2 bytes
+	cmd[10] = crc & 0xff;
+	cmd[11] = crc >> 8;
 
 	CodeIso15693AsReader(cmd, sizeof(cmd));
 }
 
+
+// do not use; has a fix UID
 static void __attribute__((unused)) BuildReadMultiBlockRequest(uint8_t *uid)
 {
 	uint8_t cmd[14];
 
 	uint16_t crc;
-	// If we set the Option_Flag in this request, the VICC will respond with the secuirty status of the block
-	// followed by teh block data
+	// If we set the Option_Flag in this request, the VICC will respond with the security status of the block
+	// followed by the block data
 	// one sub-carrier, inventory, 1 slot, fast rate
 	cmd[0] =  (1 << 5) | (1 << 1); // no SELECT bit
 	// READ Multi BLOCK command code
@@ -361,20 +1921,21 @@ static void __attribute__((unused)) BuildReadMultiBlockRequest(uint8_t *uid)
 	// Number of Blocks to read
 	cmd[11] = 0x2f; // read quite a few
 	//Now the CRC
-	crc = Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
+	crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
 	cmd[12] = crc & 0xff;
 	cmd[13] = crc >> 8;
 
 	CodeIso15693AsReader(cmd, sizeof(cmd));
 }
 
+// do not use; has a fix UID
 static void __attribute__((unused)) BuildArbitraryRequest(uint8_t *uid,uint8_t CmdCode)
 {
 	uint8_t cmd[14];
 
 	uint16_t crc;
-	// If we set the Option_Flag in this request, the VICC will respond with the secuirty status of the block
-	// followed by teh block data
+	// If we set the Option_Flag in this request, the VICC will respond with the security status of the block
+	// followed by the block data
 	// one sub-carrier, inventory, 1 slot, fast rate
 	cmd[0] =   (1 << 5) | (1 << 1); // no SELECT bit
 	// READ BLOCK command code
@@ -393,22 +1954,23 @@ static void __attribute__((unused)) BuildArbitraryRequest(uint8_t *uid,uint8_t C
 	cmd[10] = 0x00;
 	cmd[11] = 0x0a;
 
-//	cmd[12] = 0x00;
-//	cmd[13] = 0x00;	//Now the CRC
-	crc = Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
+//  cmd[12] = 0x00;
+//  cmd[13] = 0x00; //Now the CRC
+	crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
 	cmd[12] = crc & 0xff;
 	cmd[13] = crc >> 8;
 
 	CodeIso15693AsReader(cmd, sizeof(cmd));
 }
 
+// do not use; has a fix UID
 static void __attribute__((unused)) BuildArbitraryCustomRequest(uint8_t uid[], uint8_t CmdCode)
 {
 	uint8_t cmd[14];
 
 	uint16_t crc;
-	// If we set the Option_Flag in this request, the VICC will respond with the secuirty status of the block
-	// followed by teh block data
+	// If we set the Option_Flag in this request, the VICC will respond with the security status of the block
+	// followed by the block data
 	// one sub-carrier, inventory, 1 slot, fast rate
 	cmd[0] =   (1 << 5) | (1 << 1); // no SELECT bit
 	// READ BLOCK command code
@@ -424,690 +1986,21 @@ static void __attribute__((unused)) BuildArbitraryCustomRequest(uint8_t uid[], u
 	cmd[8] = 0x05;
 	cmd[9]= 0xe0; // always e0 (not exactly unique)
 	// Parameter
-	cmd[10] = 0x05; // for custom codes this must be manufcturer code
+	cmd[10] = 0x05; // for custom codes this must be manufacturer code
 	cmd[11] = 0x00;
 
-//	cmd[12] = 0x00;
-//	cmd[13] = 0x00;	//Now the CRC
-	crc = Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
+//  cmd[12] = 0x00;
+//  cmd[13] = 0x00; //Now the CRC
+	crc = Iso15693Crc(cmd, 12); // the crc needs to be calculated over 2 bytes
 	cmd[12] = crc & 0xff;
 	cmd[13] = crc >> 8;
 
 	CodeIso15693AsReader(cmd, sizeof(cmd));
 }
 
-/////////////////////////////////////////////////////////////////////////
-// Now the VICC>VCD responses when we are simulating a tag
-////////////////////////////////////////////////////////////////////
-
- static void BuildInventoryResponse(void)
-{
-	uint8_t cmd[12];
-
-	uint16_t crc;
-	// one sub-carrier, inventory, 1 slot, fast rate
-	// AFI is at bit 5 (1<<4) when doing an INVENTORY
-	cmd[0] = 0; //(1 << 2) | (1 << 5) | (1 << 1);
-	cmd[1] = 0;
-	// 64-bit UID
-	cmd[2] = 0x32;
-	cmd[3]= 0x4b;
-	cmd[4] = 0x03;
-	cmd[5] = 0x01;
-	cmd[6] = 0x00;
-	cmd[7] = 0x10;
-	cmd[8] = 0x05;
-	cmd[9]= 0xe0;
-	//Now the CRC
-	crc = Crc(cmd, 10);
-	cmd[10] = crc & 0xff;
-	cmd[11] = crc >> 8;
-
-	CodeIso15693AsReader(cmd, sizeof(cmd));
-}
-
-//-----------------------------------------------------------------------------
-// Transmit the command (to the tag) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitTo15693Tag(const uint8_t *cmd, int len, int *samples, int *wait)
-{
-    int c;
-
-//    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
-	if(*wait < 10) { *wait = 10; }
-
-//    for(c = 0; c < *wait;) {
-//        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-//            AT91C_BASE_SSC->SSC_THR = 0x00;		// For exact timing!
-//            c++;
-//        }
-//        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-//            volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-//            (void)r;
-//        }
-//        WDT_HIT();
-//    }
-
-    c = 0;
-    for(;;) {
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = cmd[c];
-            c++;
-            if(c >= len) {
-                break;
-            }
-        }
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-            (void)r;
-        }
-        WDT_HIT();
-    }
-	*samples = (c + *wait) << 3;
-}
-
-//-----------------------------------------------------------------------------
-// Transmit the command (to the reader) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitTo15693Reader(const uint8_t *cmd, int len, int *samples, int *wait)
-{
-    int c;
-
-//	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR);	// No requirement to energise my coils
-	if(*wait < 10) { *wait = 10; }
-
-    c = 0;
-    for(;;) {
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = cmd[c];
-            c++;
-            if(c >= len) {
-                break;
-            }
-        }
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-            (void)r;
-        }
-        WDT_HIT();
-    }
-	*samples = (c + *wait) << 3;
-}
-
-static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed)
-{
-	int c = 0;
-	uint8_t *dest = (uint8_t *)BigBuf;
-	int getNext = 0;
-
-	int8_t prev = 0;
-
-// NOW READ RESPONSE
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
-	//spindelay(60);	// greg - experiment to get rid of some of the 0 byte/failed reads
-	c = 0;
-	getNext = FALSE;
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = 0x43;
-		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			int8_t b;
-			b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
-
-			// The samples are correlations against I and Q versions of the
-			// tone that the tag AM-modulates, so every other sample is I,
-			// every other is Q. We just want power, so abs(I) + abs(Q) is
-			// close to what we want.
-			if(getNext) {
-				int8_t r;
-
-				if(b < 0) {
-					r = -b;
-				} else {
-					r = b;
-				}
-				if(prev < 0) {
-					r -= prev;
-				} else {
-					r += prev;
-				}
-
-				dest[c++] = (uint8_t)r;
-
-				if(c >= 2000) {
-					break;
-				}
-			} else {
-				prev = b;
-			}
-
-			getNext = !getNext;
-		}
-	}
-
-//////////////////////////////////////////
-/////////// DEMODULATE ///////////////////
-//////////////////////////////////////////
-
-	int i, j;
-	int max = 0, maxPos=0;
-
-	int skip = 4;
-
-//	if(GraphTraceLen < 1000) return;	// THIS CHECKS FOR A BUFFER TO SMALL
-
-	// First, correlate for SOF
-	for(i = 0; i < 100; i++) {
-		int corr = 0;
-		for(j = 0; j < arraylen(FrameSOF); j += skip) {
-			corr += FrameSOF[j]*dest[i+(j/skip)];
-		}
-		if(corr > max) {
-			max = corr;
-			maxPos = i;
-		}
-	}
-//	DbpString("SOF at %d, correlation %d", maxPos,max/(arraylen(FrameSOF)/skip));
-
-	int k = 0; // this will be our return value
-
-	// greg - If correlation is less than 1 then there's little point in continuing
-	if ((max/(arraylen(FrameSOF)/skip)) >= 1)
-	{
-
-	i = maxPos + arraylen(FrameSOF)/skip;
-
-	uint8_t outBuf[20];
-	memset(outBuf, 0, sizeof(outBuf));
-	uint8_t mask = 0x01;
-	for(;;) {
-		int corr0 = 0, corr1 = 0, corrEOF = 0;
-		for(j = 0; j < arraylen(Logic0); j += skip) {
-			corr0 += Logic0[j]*dest[i+(j/skip)];
-		}
-		for(j = 0; j < arraylen(Logic1); j += skip) {
-			corr1 += Logic1[j]*dest[i+(j/skip)];
-		}
-		for(j = 0; j < arraylen(FrameEOF); j += skip) {
-			corrEOF += FrameEOF[j]*dest[i+(j/skip)];
-		}
-		// Even things out by the length of the target waveform.
-		corr0 *= 4;
-		corr1 *= 4;
-
-		if(corrEOF > corr1 && corrEOF > corr0) {
-//			DbpString("EOF at %d", i);
-			break;
-		} else if(corr1 > corr0) {
-			i += arraylen(Logic1)/skip;
-			outBuf[k] |= mask;
-		} else {
-			i += arraylen(Logic0)/skip;
-		}
-		mask <<= 1;
-		if(mask == 0) {
-			k++;
-			mask = 0x01;
-		}
-		if((i+(int)arraylen(FrameEOF)) >= 2000) {
-			DbpString("ran off end!");
-			break;
-		}
-	}
-	if(mask != 0x01) {
-		DbpString("error, uneven octet! (discard extra bits!)");
-///		DbpString("   mask=%02x", mask);
-	}
-//	uint8_t str1 [8];
-//	itoa(k,str1);
-//	strcat(str1," octets read");
-
-//	DbpString(  str1);    // DbpString("%d octets", k);
-
-//	for(i = 0; i < k; i+=3) {
-//		//DbpString("# %2d: %02x ", i, outBuf[i]);
-//		DbpIntegers(outBuf[i],outBuf[i+1],outBuf[i+2]);
-//	}
-
-	for(i = 0; i < k; i++) {
-		receivedResponse[i] = outBuf[i];
-	}
-	} // "end if correlation > 0" 	(max/(arraylen(FrameSOF)/skip))
-	return k; // return the number of bytes demodulated
-
-///	DbpString("CRC=%04x", Iso15693Crc(outBuf, k-2));
-
-}
-
-// Now the GetISO15693 message from sniffing command
-static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed)
-{
-	int c = 0;
-	uint8_t *dest = (uint8_t *)BigBuf;
-	int getNext = 0;
-
-	int8_t prev = 0;
-
-// NOW READ RESPONSE
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
-	//spindelay(60);	// greg - experiment to get rid of some of the 0 byte/failed reads
-	c = 0;
-	getNext = FALSE;
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = 0x43;
-		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			int8_t b;
-			b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
-
-			// The samples are correlations against I and Q versions of the
-			// tone that the tag AM-modulates, so every other sample is I,
-			// every other is Q. We just want power, so abs(I) + abs(Q) is
-			// close to what we want.
-			if(getNext) {
-				int8_t r;
-
-				if(b < 0) {
-					r = -b;
-				} else {
-					r = b;
-				}
-				if(prev < 0) {
-					r -= prev;
-				} else {
-					r += prev;
-				}
-
-				dest[c++] = (uint8_t)r;
-
-				if(c >= 20000) {
-					break;
-				}
-			} else {
-				prev = b;
-			}
-
-			getNext = !getNext;
-		}
-	}
-
-//////////////////////////////////////////
-/////////// DEMODULATE ///////////////////
-//////////////////////////////////////////
-
-	int i, j;
-	int max = 0, maxPos=0;
-
-	int skip = 4;
-
-//	if(GraphTraceLen < 1000) return;	// THIS CHECKS FOR A BUFFER TO SMALL
-
-	// First, correlate for SOF
-	for(i = 0; i < 19000; i++) {
-		int corr = 0;
-		for(j = 0; j < arraylen(FrameSOF); j += skip) {
-			corr += FrameSOF[j]*dest[i+(j/skip)];
-		}
-		if(corr > max) {
-			max = corr;
-			maxPos = i;
-		}
-	}
-//	DbpString("SOF at %d, correlation %d", maxPos,max/(arraylen(FrameSOF)/skip));
-
-	int k = 0; // this will be our return value
-
-	// greg - If correlation is less than 1 then there's little point in continuing
-	if ((max/(arraylen(FrameSOF)/skip)) >= 1)	// THIS SHOULD BE 1
-	{
-
-	i = maxPos + arraylen(FrameSOF)/skip;
-
-	uint8_t outBuf[20];
-	memset(outBuf, 0, sizeof(outBuf));
-	uint8_t mask = 0x01;
-	for(;;) {
-		int corr0 = 0, corr1 = 0, corrEOF = 0;
-		for(j = 0; j < arraylen(Logic0); j += skip) {
-			corr0 += Logic0[j]*dest[i+(j/skip)];
-		}
-		for(j = 0; j < arraylen(Logic1); j += skip) {
-			corr1 += Logic1[j]*dest[i+(j/skip)];
-		}
-		for(j = 0; j < arraylen(FrameEOF); j += skip) {
-			corrEOF += FrameEOF[j]*dest[i+(j/skip)];
-		}
-		// Even things out by the length of the target waveform.
-		corr0 *= 4;
-		corr1 *= 4;
-
-		if(corrEOF > corr1 && corrEOF > corr0) {
-//			DbpString("EOF at %d", i);
-			break;
-		} else if(corr1 > corr0) {
-			i += arraylen(Logic1)/skip;
-			outBuf[k] |= mask;
-		} else {
-			i += arraylen(Logic0)/skip;
-		}
-		mask <<= 1;
-		if(mask == 0) {
-			k++;
-			mask = 0x01;
-		}
-		if((i+(int)arraylen(FrameEOF)) >= 2000) {
-			DbpString("ran off end!");
-			break;
-		}
-	}
-	if(mask != 0x01) {
-		DbpString("error, uneven octet! (discard extra bits!)");
-///		DbpString("   mask=%02x", mask);
-	}
-//	uint8_t str1 [8];
-//	itoa(k,str1);
-//	strcat(str1," octets read");
-
-//	DbpString(  str1);    // DbpString("%d octets", k);
-
-//	for(i = 0; i < k; i+=3) {
-//		//DbpString("# %2d: %02x ", i, outBuf[i]);
-//		DbpIntegers(outBuf[i],outBuf[i+1],outBuf[i+2]);
-//	}
-
-	for(i = 0; i < k; i++) {
-		receivedResponse[i] = outBuf[i];
-	}
-	} // "end if correlation > 0" 	(max/(arraylen(FrameSOF)/skip))
-	return k; // return the number of bytes demodulated
-
-///	DbpString("CRC=%04x", Iso15693Crc(outBuf, k-2));
-}
-
-//-----------------------------------------------------------------------------
-// Start to read an ISO 15693 tag. We send an identify request, then wait
-// for the response. The response is not demodulated, just left in the buffer
-// so that it can be downloaded to a PC and processed there.
-//-----------------------------------------------------------------------------
-void AcquireRawAdcSamplesIso15693(void)
-{
-	int c = 0;
-	uint8_t *dest = (uint8_t *)BigBuf;
-	int getNext = 0;
-
-	int8_t prev = 0;
-
-	BuildIdentifyRequest();
-
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-	// Give the tags time to energize
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
-	SpinDelay(100);
-
-	// Now send the command
-	FpgaSetupSsc();
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
-
-	c = 0;
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = ToSend[c];
-			c++;
-			if(c == ToSendMax+3) {
-				break;
-			}
-		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-			(void)r;
-		}
-		WDT_HIT();
-	}
-
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
-
-	c = 0;
-	getNext = FALSE;
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = 0x43;
-		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			int8_t b;
-			b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
-
-			// The samples are correlations against I and Q versions of the
-			// tone that the tag AM-modulates, so every other sample is I,
-			// every other is Q. We just want power, so abs(I) + abs(Q) is
-			// close to what we want.
-			if(getNext) {
-				int8_t r;
-
-				if(b < 0) {
-					r = -b;
-				} else {
-					r = b;
-				}
-				if(prev < 0) {
-					r -= prev;
-				} else {
-					r += prev;
-				}
-
-				dest[c++] = (uint8_t)r;
-
-				if(c >= 2000) {
-					break;
-				}
-			} else {
-				prev = b;
-			}
-
-			getNext = !getNext;
-		}
-	}
-}
-
-//-----------------------------------------------------------------------------
-// Simulate an ISO15693 reader, perform anti-collision and then attempt to read a sector
-// all demodulation performed in arm rather than host. - greg
-//-----------------------------------------------------------------------------
-void ReaderIso15693(uint32_t parameter)
-{
-	LED_A_ON();
-	LED_B_ON();
-	LED_C_OFF();
-	LED_D_OFF();
-
-//DbpString(parameter);
-
-	//uint8_t *answer0 = (((uint8_t *)BigBuf) + 3560); // allow 100 bytes per reponse (way too much)
-	uint8_t *answer1 = (((uint8_t *)BigBuf) + 3660); //
-	uint8_t *answer2 = (((uint8_t *)BigBuf) + 3760);
-	uint8_t *answer3 = (((uint8_t *)BigBuf) + 3860);
-	//uint8_t *TagUID= (((uint8_t *)BigBuf) + 3960);		// where we hold the uid for hi15reader
-//	int answerLen0 = 0;
-	int answerLen1 = 0;
-	int answerLen2 = 0;
-	int answerLen3 = 0;
-
-	// Blank arrays
-	memset(BigBuf + 3660, 0, 300);
-
-	// Setup SSC
-	FpgaSetupSsc();
-
-	// Start from off (no field generated)
-    	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    	SpinDelay(200);
-
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-	FpgaSetupSsc();
-
-	// Give the tags time to energize
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
-	SpinDelay(200);
-
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
-	LED_D_OFF();
-
-	int samples = 0;
-	int tsamples = 0;
-	int wait = 0;
-	int elapsed = 0;
-
-	// FIRST WE RUN AN INVENTORY TO GET THE TAG UID
-	// THIS MEANS WE CAN PRE-BUILD REQUESTS TO SAVE CPU TIME
- uint8_t TagUID[7];		// where we hold the uid for hi15reader
-
-//	BuildIdentifyRequest();
-//	//TransmitTo15693Tag(ToSend,ToSendMax+3,&tsamples, &wait);
-//	TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);	// No longer ToSendMax+3
-//	// Now wait for a response
-//	responseLen0 = GetIso15693AnswerFromTag(receivedAnswer0, 100, &samples, &elapsed) ;
-//	if (responseLen0 >=12) // we should do a better check than this
-//	{
-//		// really we should check it is a valid mesg
-//		// but for now just grab what we think is the uid
-//		TagUID[0] = receivedAnswer0[2];
-//		TagUID[1] = receivedAnswer0[3];
-//		TagUID[2] = receivedAnswer0[4];
-//		TagUID[3] = receivedAnswer0[5];
-//		TagUID[4] = receivedAnswer0[6];
-//		TagUID[5] = receivedAnswer0[7];
-//		TagUID[6] = receivedAnswer0[8]; // IC Manufacturer code
-//	DbpIntegers(TagUID[6],TagUID[5],TagUID[4]);
-//}
-
-	// Now send the IDENTIFY command
-	BuildIdentifyRequest();
-	//TransmitTo15693Tag(ToSend,ToSendMax+3,&tsamples, &wait);
-	TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);	// No longer ToSendMax+3
-	// Now wait for a response
-	answerLen1 = GetIso15693AnswerFromTag(answer1, 100, &samples, &elapsed) ;
-
-	if (answerLen1 >=12) // we should do a better check than this
-	{
-
-		TagUID[0] = answer1[2];
-		TagUID[1] = answer1[3];
-		TagUID[2] = answer1[4];
-		TagUID[3] = answer1[5];
-		TagUID[4] = answer1[6];
-		TagUID[5] = answer1[7];
-		TagUID[6] = answer1[8]; // IC Manufacturer code
-
-		// Now send the SELECT command
-		BuildSelectRequest(TagUID);
-		TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);	// No longer ToSendMax+3
-		// Now wait for a response
-		answerLen2 = GetIso15693AnswerFromTag(answer2, 100, &samples, &elapsed);
-
-		// Now send the MULTI READ command
-//		BuildArbitraryRequest(*TagUID,parameter);
-		BuildArbitraryCustomRequest(TagUID,parameter);
-//		BuildReadBlockRequest(*TagUID,parameter);
-//		BuildSysInfoRequest(*TagUID);
-		//TransmitTo15693Tag(ToSend,ToSendMax+3,&tsamples, &wait);
-		TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);	// No longer ToSendMax+3
-		// Now wait for a response
-		answerLen3 = GetIso15693AnswerFromTag(answer3, 100, &samples, &elapsed) ;
-
-	}
-
-	Dbprintf("%d octets read from IDENTIFY request: %x %x %x %x %x %x %x %x %x", answerLen1,
-		answer1[0], answer1[1], answer1[2],
-		answer1[3], answer1[4], answer1[5],
-		answer1[6], answer1[7], answer1[8]);
-
-	Dbprintf("%d octets read from SELECT request: %x %x %x %x %x %x %x %x %x", answerLen2,
-		answer2[0], answer2[1], answer2[2],
-		answer2[3], answer2[4], answer2[5],
-		answer2[6], answer2[7], answer2[8]);
-
-	Dbprintf("%d octets read from XXX request: %x %x %x %x %x %x %x %x %x", answerLen3,
-		answer3[0], answer3[1], answer3[2],
-		answer3[3], answer3[4], answer3[5],
-		answer3[6], answer3[7], answer3[8]);
-
-
-//	str2[0]=0;
-//	for(i = 0; i < responseLen3; i++) {
-//		itoa(str1,receivedAnswer3[i]);
-//		strcat(str2,str1);
-//	}
-//	DbpString(str2);
-
-	LED_A_OFF();
-	LED_B_OFF();
-	LED_C_OFF();
-	LED_D_OFF();
-}
-
-//-----------------------------------------------------------------------------
-// Simulate an ISO15693 TAG, perform anti-collision and then print any reader commands
-// all demodulation performed in arm rather than host. - greg
-//-----------------------------------------------------------------------------
-void SimTagIso15693(uint32_t parameter)
-{
-	LED_A_ON();
-	LED_B_ON();
-	LED_C_OFF();
-	LED_D_OFF();
-
-	uint8_t *answer1 = (((uint8_t *)BigBuf) + 3660); //
-	int answerLen1 = 0;
-
-	// Blank arrays
-	memset(answer1, 0, 100);
-
-	// Setup SSC
-	FpgaSetupSsc();
-
-	// Start from off (no field generated)
-    	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    	SpinDelay(200);
 
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-	FpgaSetupSsc();
-
-	// Give the tags time to energize
-//	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);	// NO GOOD FOR SIM TAG!!!!
-	SpinDelay(200);
-
-	LED_A_OFF();
-	LED_B_OFF();
-	LED_C_ON();
-	LED_D_OFF();
 
-	int samples = 0;
-	int tsamples = 0;
-	int wait = 0;
-	int elapsed = 0;
-
-	answerLen1 = GetIso15693AnswerFromSniff(answer1, 100, &samples, &elapsed) ;
 
-	if (answerLen1 >=1) // we should do a better check than this
-	{
-		// Build a suitable reponse to the reader INVENTORY cocmmand
-		BuildInventoryResponse();
-		TransmitTo15693Reader(ToSend,ToSendMax, &tsamples, &wait);
-	}
+*/
 
-	Dbprintf("%d octets read from reader command: %x %x %x %x %x %x %x %x %x", answerLen1,
-		answer1[0], answer1[1], answer1[2],
-		answer1[3], answer1[4], answer1[5],
-		answer1[6], answer1[7], answer1[8]);
 
-	LED_A_OFF();
-	LED_B_OFF();
-	LED_C_OFF();
-	LED_D_OFF();
-}