+//====================================================================
+// prepares data bits intreleaved with parity bits
+// see EM4469 spec
+//====================================================================
+uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
+
+ register uint8_t line_parity;
+ register uint8_t column_parity;
+ register uint8_t i, j;
+ register uint16_t data;
+
+ data = data_low;
+ column_parity = 0;
+
+ for(i=0; i<4; i++) {
+ line_parity = 0;
+ for(j=0; j<8; j++) {
+ line_parity ^= data;
+ column_parity ^= (data & 1) << j;
+ *forward_ptr++ = data;
+ data >>= 1;
+ }
+ *forward_ptr++ = line_parity;
+ if(i == 1)
+ data = data_hi;
+ }
+
+ for(j=0; j<8; j++) {
+ *forward_ptr++ = column_parity;
+ column_parity >>= 1;
+ }
+ *forward_ptr = 0;
+
+ return 45; //return number of emited bits
+}
+
+//====================================================================
+// Forward Link send function
+// Requires: forwarLink_data filled with valid bits (1 bit per byte)
+// fwd_bit_count set with number of bits to be sent
+//====================================================================
+void SendForward(uint8_t fwd_bit_count) {
+
+ fwd_write_ptr = forwardLink_data;
+ fwd_bit_sz = fwd_bit_count;
+
+ // Set up FPGA, 125kHz or 95 divisor
+ LFSetupFPGAForADC(95, true);
+
+ // force 1st mod pulse (start gap must be longer for 4305)
+ fwd_bit_sz--; //prepare next bit modulation
+ fwd_write_ptr++;
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ WaitUS(55*8); //55 cycles off (8us each)for 4305 //another reader has 37 here...
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+ WaitUS(18*8); //18 cycles on (8us each)
+
+ // now start writting
+ while(fwd_bit_sz-- > 0) { //prepare next bit modulation
+ if(((*fwd_write_ptr++) & 1) == 1)
+ WaitUS(32*8); //32 cycles at 125Khz (8us each)
+ else {
+ //These timings work for 4469/4269/4305 (with the 55*8 above)
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ WaitUS(23*8); //23 cycles off (8us each)
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+ WaitUS(18*8); //18 cycles on (8us each)
+ }
+ }
+}
+
+void EM4xLogin(uint32_t Password) {
+
+ uint8_t fwd_bit_count;
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
+ fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
+
+ SendForward(fwd_bit_count);
+
+ //Wait for command to complete
+ SpinDelay(20);
+}
+
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+ uint8_t fwd_bit_count;
+
+ // Clear destination buffer before sending the command
+ BigBuf_Clear_ext(false);
+
+ LED_A_ON();
+ StartTicks();
+ //If password mode do login
+ if (PwdMode == 1) EM4xLogin(Pwd);
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
+ fwd_bit_count += Prepare_Addr( Address );
+
+ SendForward(fwd_bit_count);
+ WaitUS(400);
+ // Now do the acquisition
+ DoPartialAcquisition(20, true, 6000, 1000);
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+ LED_A_OFF();
+ cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+void EM4xWriteWord(uint32_t flag, uint32_t Data, uint32_t Pwd) {
+
+ bool PwdMode = (flag & 0xF);
+ uint8_t Address = (flag >> 8) & 0xFF;
+ uint8_t fwd_bit_count;
+
+ //clear buffer now so it does not interfere with timing later
+ BigBuf_Clear_ext(false);
+
+ LED_A_ON();
+ StartTicks();
+ //If password mode do login
+ if (PwdMode) EM4xLogin(Pwd);
+
+ forward_ptr = forwardLink_data;
+ fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
+ fwd_bit_count += Prepare_Addr( Address );
+ fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+ SendForward(fwd_bit_count);
+
+ //Wait for write to complete
+ //SpinDelay(10);
projects / proxmark3-svn / blobdiff