X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/d24438f85c6549479b7ca00e1096c1a7cde15e5b..c936a22f1921f5dd8ebf49a8d1a0fab60337dd31:/armsrc/iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index a02d7d42..d5dd05ca 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1,1758 +1,2768 @@
-//-----------------------------------------------------------------------------
-// Routines to support ISO 14443 type A.
-//
-// Gerhard de Koning Gans - May 2008
-//-----------------------------------------------------------------------------
-#include <proxmark3.h>
-#include "apps.h"
-#include "../common/iso14443_crc.c"
-
-static BYTE *trace = (BYTE *) BigBuf;
-static int traceLen = 0;
-static int rsamples = 0;
-
-typedef enum {
-	SEC_D = 1,
-	SEC_E = 2,
-	SEC_F = 3,
-	SEC_X = 4,
-	SEC_Y = 5,
-	SEC_Z = 6
-} SecType;
-
-static const BYTE OddByteParity[256] = {
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
-};
-
-//-----------------------------------------------------------------------------
-// Generate the parity value for a byte sequence
-// 
-//-----------------------------------------------------------------------------
-DWORD GetParity(const BYTE * pbtCmd, int iLen)
-{
-  int i;
-  DWORD dwPar = 0;
-  
-  // Generate the encrypted data
-  for (i = 0; i < iLen; i++) {
-    // Save the encrypted parity bit
-    dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
-  }
-  return dwPar;
-}
-
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
-//-----------------------------------------------------------------------------
-static struct {
-    enum {
-        STATE_UNSYNCD,
-        STATE_START_OF_COMMUNICATION,
-		STATE_MILLER_X,
-		STATE_MILLER_Y,
-		STATE_MILLER_Z,
-        STATE_ERROR_WAIT
-    }       state;
-    WORD    shiftReg;
-    int     bitCnt;
-    int     byteCnt;
-    int     byteCntMax;
-    int     posCnt;
-    int     syncBit;
-	int     parityBits;
-	int     samples;
-    int     highCnt;
-    int     bitBuffer;
-	enum {
-		DROP_NONE,
-		DROP_FIRST_HALF,
-		DROP_SECOND_HALF
-	}		drop;
-    BYTE   *output;
-} Uart;
-
-static BOOL MillerDecoding(int bit)
-{
-	int error = 0;
-	int bitright;
-
-	if(!Uart.bitBuffer) {
-		Uart.bitBuffer = bit ^ 0xFF0;
-		return FALSE;
-	}
-	else {
-		Uart.bitBuffer <<= 4;
-		Uart.bitBuffer ^= bit;
-	}
-
-	BOOL EOC = FALSE;
-
-	if(Uart.state != STATE_UNSYNCD) {
-		Uart.posCnt++;
-
-		if((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit) {
-			bit = 0x00;
-		}
-		else {
-			bit = 0x01;
-		}
-		if(((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit) {
-			bitright = 0x00;
-		}
-		else {
-			bitright = 0x01;
-		}
-		if(bit != bitright) { bit = bitright; }
-
-		if(Uart.posCnt == 1) {
-			// measurement first half bitperiod
-			if(!bit) {
-				Uart.drop = DROP_FIRST_HALF;
-			}
-		}
-		else {
-			// measurement second half bitperiod
-			if(!bit & (Uart.drop == DROP_NONE)) {
-				Uart.drop = DROP_SECOND_HALF;
-			}
-			else if(!bit) {
-				// measured a drop in first and second half
-				// which should not be possible
-				Uart.state = STATE_ERROR_WAIT;
-				error = 0x01;
-			}
-
-			Uart.posCnt = 0;
-
-			switch(Uart.state) {
-				case STATE_START_OF_COMMUNICATION:
-					Uart.shiftReg = 0;
-					if(Uart.drop == DROP_SECOND_HALF) {
-						// error, should not happen in SOC
-						Uart.state = STATE_ERROR_WAIT;
-						error = 0x02;
-					}
-					else {
-						// correct SOC
-						Uart.state = STATE_MILLER_Z;
-					}
-					break;
-
-				case STATE_MILLER_Z:
-					Uart.bitCnt++;
-					Uart.shiftReg >>= 1;
-					if(Uart.drop == DROP_NONE) {
-						// logic '0' followed by sequence Y
-						// end of communication
-						Uart.state = STATE_UNSYNCD;
-						EOC = TRUE;
-					}
-					// if(Uart.drop == DROP_FIRST_HALF) {
-					// 	Uart.state = STATE_MILLER_Z; stay the same
-					// 	we see a logic '0' }
-					if(Uart.drop == DROP_SECOND_HALF) {
-						// we see a logic '1'
-						Uart.shiftReg |= 0x100;
-						Uart.state = STATE_MILLER_X;
-					}
-					break;
-
-				case STATE_MILLER_X:
-					Uart.shiftReg >>= 1;
-					if(Uart.drop == DROP_NONE) {
-						// sequence Y, we see a '0'
-						Uart.state = STATE_MILLER_Y;
-						Uart.bitCnt++;
-					}
-					if(Uart.drop == DROP_FIRST_HALF) {
-						// Would be STATE_MILLER_Z
-						// but Z does not follow X, so error
-						Uart.state = STATE_ERROR_WAIT;
-						error = 0x03;
-					}
-					if(Uart.drop == DROP_SECOND_HALF) {
-						// We see a '1' and stay in state X
-						Uart.shiftReg |= 0x100;
-						Uart.bitCnt++;
-					}
-					break;
-
-				case STATE_MILLER_Y:
-					Uart.bitCnt++;
-					Uart.shiftReg >>= 1;
-					if(Uart.drop == DROP_NONE) {
-						// logic '0' followed by sequence Y
-						// end of communication
-						Uart.state = STATE_UNSYNCD;
-						EOC = TRUE;
-					}
-					if(Uart.drop == DROP_FIRST_HALF) {
-						// we see a '0'
-						Uart.state = STATE_MILLER_Z;
-					}
-					if(Uart.drop == DROP_SECOND_HALF) {
-						// We see a '1' and go to state X
-						Uart.shiftReg |= 0x100;
-						Uart.state = STATE_MILLER_X;
-					}
-					break;
-
-				case STATE_ERROR_WAIT:
-					// That went wrong. Now wait for at least two bit periods
-					// and try to sync again
-					if(Uart.drop == DROP_NONE) {
-						Uart.highCnt = 6;
-						Uart.state = STATE_UNSYNCD;
-					}
-					break;
-
-				default:
-					Uart.state = STATE_UNSYNCD;
-					Uart.highCnt = 0;
-					break;
-			}
-
-			Uart.drop = DROP_NONE;
-
-			// should have received at least one whole byte...
-			if((Uart.bitCnt == 2) && EOC && (Uart.byteCnt > 0)) {
-				return TRUE;
-			}
-
-			if(Uart.bitCnt == 9) {
-				Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
-				Uart.byteCnt++;
-
-				Uart.parityBits <<= 1;
-				Uart.parityBits ^= ((Uart.shiftReg >> 8) & 0x01);
-
-				if(EOC) {
-					// when End of Communication received and
-					// all data bits processed..
-					return TRUE;
-				}
-				Uart.bitCnt = 0;
-			}
-
-			/*if(error) {
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = error & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = (Uart.bitBuffer >> 8) & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = (Uart.syncBit >> 3) & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				return TRUE;
-			}*/
-		}
-
-	}
-	else {
-		bit = Uart.bitBuffer & 0xf0;
-		bit >>= 4;
-		bit ^= 0x0F;
-		if(bit) {
-			// should have been high or at least (4 * 128) / fc
-			// according to ISO this should be at least (9 * 128 + 20) / fc
-			if(Uart.highCnt == 8) {
-				// we went low, so this could be start of communication
-				// it turns out to be safer to choose a less significant
-				// syncbit... so we check whether the neighbour also represents the drop
-				Uart.posCnt = 1;   // apparently we are busy with our first half bit period
-				Uart.syncBit = bit & 8;
-				Uart.samples = 3;
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 4; Uart.samples = 2; }
-				else if(bit & 4)	{ Uart.syncBit = bit & 4; Uart.samples = 2; bit <<= 2; }
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 2; Uart.samples = 1; }
-				else if(bit & 2)	{ Uart.syncBit = bit & 2; Uart.samples = 1; bit <<= 1; }
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 1; Uart.samples = 0;
-					if(Uart.syncBit & (Uart.bitBuffer & 8)) {
-						Uart.syncBit = 8;
-
-						// the first half bit period is expected in next sample
-						Uart.posCnt = 0;
-						Uart.samples = 3;
-					}
-				}
-				else if(bit & 1)	{ Uart.syncBit = bit & 1; Uart.samples = 0; }
-
-				Uart.syncBit <<= 4;
-				Uart.state = STATE_START_OF_COMMUNICATION;
-				Uart.drop = DROP_FIRST_HALF;
-				Uart.bitCnt = 0;
-				Uart.byteCnt = 0;
-				Uart.parityBits = 0;
-				error = 0;
-			}
-			else {
-				Uart.highCnt = 0;
-			}
-		}
-		else {
-			if(Uart.highCnt < 8) {
-				Uart.highCnt++;
-			}
-		}
-	}
-
-    return FALSE;
-}
-
-//=============================================================================
-// ISO 14443 Type A - Manchester
-//=============================================================================
-
-static struct {
-    enum {
-        DEMOD_UNSYNCD,
-		DEMOD_START_OF_COMMUNICATION,
-		DEMOD_MANCHESTER_D,
-		DEMOD_MANCHESTER_E,
-		DEMOD_MANCHESTER_F,
-        DEMOD_ERROR_WAIT
-    }       state;
-    int     bitCount;
-    int     posCount;
-	int     syncBit;
-	int     parityBits;
-    WORD    shiftReg;
-	int     buffer;
-	int     buff;
-	int     samples;
-    int     len;
-	enum {
-		SUB_NONE,
-		SUB_FIRST_HALF,
-		SUB_SECOND_HALF
-	}		sub;
-    BYTE   *output;
-} Demod;
-
-static BOOL ManchesterDecoding(int v)
-{
-	int bit;
-	int modulation;
-	int error = 0;
-
-	if(!Demod.buff) {
-		Demod.buff = 1;
-		Demod.buffer = v;
-		return FALSE;
-	}
-	else {
-		bit = Demod.buffer;
-		Demod.buffer = v;
-	}
-
-	if(Demod.state==DEMOD_UNSYNCD) {
-		Demod.output[Demod.len] = 0xfa;
-		Demod.syncBit = 0;
-		//Demod.samples = 0;
-		Demod.posCount = 1;		// This is the first half bit period, so after syncing handle the second part
-		if(bit & 0x08) { Demod.syncBit = 0x08; }
-		if(!Demod.syncBit)	{
-			if(bit & 0x04) { Demod.syncBit = 0x04; }
-		}
-		else if(bit & 0x04) { Demod.syncBit = 0x04; bit <<= 4; }
-		if(!Demod.syncBit)	{
-			if(bit & 0x02) { Demod.syncBit = 0x02; }
-		}
-		else if(bit & 0x02) { Demod.syncBit = 0x02; bit <<= 4; }
-		if(!Demod.syncBit)	{
-			if(bit & 0x01) { Demod.syncBit = 0x01; }
-
-			if(Demod.syncBit & (Demod.buffer & 0x08)) {
-				Demod.syncBit = 0x08;
-
-				// The first half bitperiod is expected in next sample
-				Demod.posCount = 0;
-				Demod.output[Demod.len] = 0xfb;
-			}
-		}
-		else if(bit & 0x01) { Demod.syncBit = 0x01; }
-
-		if(Demod.syncBit) {
-			Demod.len = 0;
-			Demod.state = DEMOD_START_OF_COMMUNICATION;
-			Demod.sub = SUB_FIRST_HALF;
-			Demod.bitCount = 0;
-			Demod.shiftReg = 0;
-			Demod.parityBits = 0;
-			Demod.samples = 0;
-			if(Demod.posCount) {
-				switch(Demod.syncBit) {
-					case 0x08: Demod.samples = 3; break;
-					case 0x04: Demod.samples = 2; break;
-					case 0x02: Demod.samples = 1; break;
-					case 0x01: Demod.samples = 0; break;
-				}
-			}
-			error = 0;
-		}
-	}
-	else {
-		//modulation = bit & Demod.syncBit;
-		modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
-
-		Demod.samples += 4;
-
-		if(Demod.posCount==0) {
-			Demod.posCount = 1;
-			if(modulation) {
-				Demod.sub = SUB_FIRST_HALF;
-			}
-			else {
-				Demod.sub = SUB_NONE;
-			}
-		}
-		else {
-			Demod.posCount = 0;
-			if(modulation && (Demod.sub == SUB_FIRST_HALF)) {
-				if(Demod.state!=DEMOD_ERROR_WAIT) {
-					Demod.state = DEMOD_ERROR_WAIT;
-					Demod.output[Demod.len] = 0xaa;
-					error = 0x01;
-				}
-			}
-			else if(modulation) {
-				Demod.sub = SUB_SECOND_HALF;
-			}
-
-			switch(Demod.state) {
-				case DEMOD_START_OF_COMMUNICATION:
-					if(Demod.sub == SUB_FIRST_HALF) {
-						Demod.state = DEMOD_MANCHESTER_D;
-					}
-					else {
-						Demod.output[Demod.len] = 0xab;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x02;
-					}
-					break;
-
-				case DEMOD_MANCHESTER_D:
-				case DEMOD_MANCHESTER_E:
-					if(Demod.sub == SUB_FIRST_HALF) {
-						Demod.bitCount++;
-						Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100;
-						Demod.state = DEMOD_MANCHESTER_D;
-					}
-					else if(Demod.sub == SUB_SECOND_HALF) {
-						Demod.bitCount++;
-						Demod.shiftReg >>= 1;
-						Demod.state = DEMOD_MANCHESTER_E;
-					}
-					else {
-						Demod.state = DEMOD_MANCHESTER_F;
-					}
-					break;
-
-				case DEMOD_MANCHESTER_F:
-					// Tag response does not need to be a complete byte!
-					if(Demod.len > 0 || Demod.bitCount > 0) {
-						if(Demod.bitCount > 0) {
-							Demod.shiftReg >>= (9 - Demod.bitCount);
-							Demod.output[Demod.len] = Demod.shiftReg & 0xff;
-							Demod.len++;
-							// No parity bit, so just shift a 0
-							Demod.parityBits <<= 1;
-						}
-
-						Demod.state = DEMOD_UNSYNCD;
-						return TRUE;
-					}
-					else {
-						Demod.output[Demod.len] = 0xad;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x03;
-					}
-					break;
-
-				case DEMOD_ERROR_WAIT:
-					Demod.state = DEMOD_UNSYNCD;
-					break;
-
-				default:
-					Demod.output[Demod.len] = 0xdd;
-					Demod.state = DEMOD_UNSYNCD;
-					break;
-			}
-
-			if(Demod.bitCount>=9) {
-				Demod.output[Demod.len] = Demod.shiftReg & 0xff;
-				Demod.len++;
-
-				Demod.parityBits <<= 1;
-				Demod.parityBits ^= ((Demod.shiftReg >> 8) & 0x01);
-
-				Demod.bitCount = 0;
-				Demod.shiftReg = 0;
-			}
-
-			/*if(error) {
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				Demod.output[Demod.len] = error & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				Demod.output[Demod.len] = bit & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = Demod.buffer & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = Demod.syncBit & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				return TRUE;
-			}*/
-
-		}
-
-	} // end (state != UNSYNCED)
-
-    return FALSE;
-}
-
-//=============================================================================
-// Finally, a `sniffer' for ISO 14443 Type A
-// Both sides of communication!
-//=============================================================================
-
-//-----------------------------------------------------------------------------
-// Record the sequence of commands sent by the reader to the tag, with
-// triggering so that we start recording at the point that the tag is moved
-// near the reader.
-//-----------------------------------------------------------------------------
-void SnoopIso14443a(void)
-{
-
-	// BIG CHANGE - UNDERSTAND THIS BEFORE WE COMMIT
-
-	#define RECV_CMD_OFFSET 	3032
-	#define RECV_RES_OFFSET		3096
-	#define DMA_BUFFER_OFFSET	3160
-	#define DMA_BUFFER_SIZE 	4096
-	#define TRACE_LENGTH	 	3000
-
-//	#define RECV_CMD_OFFSET 	2032	// original (working as of 21/2/09) values
-//	#define RECV_RES_OFFSET		2096	// original (working as of 21/2/09) values
-//	#define DMA_BUFFER_OFFSET	2160	// original (working as of 21/2/09) values
-//	#define DMA_BUFFER_SIZE 	4096	// original (working as of 21/2/09) values
-//	#define TRACE_LENGTH	 	2000	// original (working as of 21/2/09) values
-
-    // We won't start recording the frames that we acquire until we trigger;
-    // a good trigger condition to get started is probably when we see a
-    // response from the tag.
-    BOOL triggered = TRUE; // FALSE to wait first for card
-
-    // The command (reader -> tag) that we're receiving.
-	// The length of a received command will in most cases be no more than 18 bytes.
-	// So 32 should be enough!
-    BYTE *receivedCmd = (((BYTE *)BigBuf) + RECV_CMD_OFFSET);
-    // The response (tag -> reader) that we're receiving.
-    BYTE *receivedResponse = (((BYTE *)BigBuf) + RECV_RES_OFFSET);
-
-    // As we receive stuff, we copy it from receivedCmd or receivedResponse
-    // into trace, along with its length and other annotations.
-    //BYTE *trace = (BYTE *)BigBuf;
-    //int traceLen = 0;
-
-    // The DMA buffer, used to stream samples from the FPGA
-    SBYTE *dmaBuf = ((SBYTE *)BigBuf) + DMA_BUFFER_OFFSET;
-    int lastRxCounter;
-    SBYTE *upTo;
-    int smpl;
-    int maxBehindBy = 0;
-
-    // Count of samples received so far, so that we can include timing
-    // information in the trace buffer.
-    int samples = 0;
-	int rsamples = 0;
-
-    memset(trace, 0x44, RECV_CMD_OFFSET);
-
-    // Set up the demodulator for tag -> reader responses.
-    Demod.output = receivedResponse;
-    Demod.len = 0;
-    Demod.state = DEMOD_UNSYNCD;
-
-    // And the reader -> tag commands
-    memset(&Uart, 0, sizeof(Uart));
-    Uart.output = receivedCmd;
-    Uart.byteCntMax = 32; // was 100 (greg)////////////////////////////////////////////////////////////////////////
-    Uart.state = STATE_UNSYNCD;
-
-    // And put the FPGA in the appropriate mode
-    // Signal field is off with the appropriate LED
-    LED_D_OFF();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
-    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-	// Setup for the DMA.
-    FpgaSetupSsc();
-    upTo = dmaBuf;
-    lastRxCounter = DMA_BUFFER_SIZE;
-    FpgaSetupSscDma((BYTE *)dmaBuf, DMA_BUFFER_SIZE);
-
-    LED_A_ON();
-
-    // And now we loop, receiving samples.
-    for(;;) {
-		WDT_HIT();
-        int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
-                                (DMA_BUFFER_SIZE-1);
-        if(behindBy > maxBehindBy) {
-            maxBehindBy = behindBy;
-            if(behindBy > 400) {
-                DbpString("blew circular buffer!");
-                goto done;
-            }
-        }
-        if(behindBy < 1) continue;
-
-        smpl = upTo[0];
-        upTo++;
-        lastRxCounter -= 1;
-        if(upTo - dmaBuf > DMA_BUFFER_SIZE) {
-            upTo -= DMA_BUFFER_SIZE;
-            lastRxCounter += DMA_BUFFER_SIZE;
-            AT91C_BASE_PDC_SSC->PDC_RNPR = (DWORD)upTo;
-            AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
-        }
-
-        samples += 4;
-#define HANDLE_BIT_IF_BODY \
-            LED_C_ON(); \
-			if(triggered) { \
-				trace[traceLen++] = ((rsamples >>  0) & 0xff); \
-                trace[traceLen++] = ((rsamples >>  8) & 0xff); \
-                trace[traceLen++] = ((rsamples >> 16) & 0xff); \
-                trace[traceLen++] = ((rsamples >> 24) & 0xff); \
-				trace[traceLen++] = ((Uart.parityBits >>  0) & 0xff); \
-				trace[traceLen++] = ((Uart.parityBits >>  8) & 0xff); \
-				trace[traceLen++] = ((Uart.parityBits >> 16) & 0xff); \
-				trace[traceLen++] = ((Uart.parityBits >> 24) & 0xff); \
-                trace[traceLen++] = Uart.byteCnt; \
-                memcpy(trace+traceLen, receivedCmd, Uart.byteCnt); \
-                traceLen += Uart.byteCnt; \
-                if(traceLen > TRACE_LENGTH) break; \
-            } \
-            /* And ready to receive another command. */ \
-            Uart.state = STATE_UNSYNCD; \
-            /* And also reset the demod code, which might have been */ \
-            /* false-triggered by the commands from the reader. */ \
-            Demod.state = DEMOD_UNSYNCD; \
-			LED_B_OFF(); \
-
-		if(MillerDecoding((smpl & 0xF0) >> 4)) {
-            rsamples = samples - Uart.samples;
-			HANDLE_BIT_IF_BODY
-        }
-		if(ManchesterDecoding(smpl & 0x0F)) {
-			rsamples = samples - Demod.samples;
-			LED_B_ON();
-
-			// timestamp, as a count of samples
-			trace[traceLen++] = ((rsamples >>  0) & 0xff);
-			trace[traceLen++] = ((rsamples >>  8) & 0xff);
-			trace[traceLen++] = ((rsamples >> 16) & 0xff);
-			trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff);
-			trace[traceLen++] = ((Demod.parityBits >>  0) & 0xff);
-			trace[traceLen++] = ((Demod.parityBits >>  8) & 0xff);
-			trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff);
-			trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff);
-			// length
-			trace[traceLen++] = Demod.len;
-			memcpy(trace+traceLen, receivedResponse, Demod.len);
-			traceLen += Demod.len;
-			if(traceLen > TRACE_LENGTH) break;
-
-           	triggered = TRUE;
-
-            // And ready to receive another response.
-            memset(&Demod, 0, sizeof(Demod));
-            Demod.output = receivedResponse;
-            Demod.state = DEMOD_UNSYNCD;
-			LED_C_OFF();
-		}
-
-        if(BUTTON_PRESS()) {
-            DbpString("cancelled_a");
-            goto done;
-        }
-    }
-
-    DbpString("COMMAND FINISHED");
-
-    DbpIntegers(maxBehindBy, Uart.state, Uart.byteCnt);
-    DbpIntegers(Uart.byteCntMax, traceLen, (int)Uart.output[0]);
-
-done:
-    AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
-    DbpIntegers(maxBehindBy, Uart.state, Uart.byteCnt);
-    DbpIntegers(Uart.byteCntMax, traceLen, (int)Uart.output[0]);
-    LED_A_OFF();
-    LED_B_OFF();
-	LED_C_OFF();
-	LED_D_OFF();
-}
-
-// Prepare communication bits to send to FPGA
-void Sequence(SecType seq)
-{
-	ToSendMax++;
-	switch(seq) {
-	// CARD TO READER
-	case SEC_D:
-		// Sequence D: 11110000
-		// modulation with subcarrier during first half
-        ToSend[ToSendMax] = 0xf0;
-		break;
-	case SEC_E:
-		// Sequence E: 00001111
-		// modulation with subcarrier during second half
-        ToSend[ToSendMax] = 0x0f;
-		break;
-	case SEC_F:
-		// Sequence F: 00000000
-		// no modulation with subcarrier
-        ToSend[ToSendMax] = 0x00;
-		break;
-	// READER TO CARD
-	case SEC_X:
-		// Sequence X: 00001100
-		// drop after half a period
-        ToSend[ToSendMax] = 0x0c;
-		break;
-	case SEC_Y:
-	default:
-		// Sequence Y: 00000000
-		// no drop
-        ToSend[ToSendMax] = 0x00;
-		break;
-	case SEC_Z:
-		// Sequence Z: 11000000
-		// drop at start
-        ToSend[ToSendMax] = 0xc0;
-		break;
-	}
-}
-
-//-----------------------------------------------------------------------------
-// Prepare tag messages
-//-----------------------------------------------------------------------------
-static void CodeIso14443aAsTag(const BYTE *cmd, int len)
-{
-    int i;
-	int oddparity;
-
-    ToSendReset();
-
-	// Correction bit, might be removed when not needed
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(1);  // 1
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-
-	// Send startbit
-	Sequence(SEC_D);
-
-    for(i = 0; i < len; i++) {
-        int j;
-        BYTE b = cmd[i];
-
-		// Data bits
-        oddparity = 0x01;
-		for(j = 0; j < 8; j++) {
-            oddparity ^= (b & 1);
-			if(b & 1) {
-				Sequence(SEC_D);
-			} else {
-				Sequence(SEC_E);
-            }
-            b >>= 1;
-        }
-
-        // Parity bit
-        if(oddparity) {
-			Sequence(SEC_D);
-		} else {
-			Sequence(SEC_E);
-		}
-    }
-
-    // Send stopbit
-	Sequence(SEC_F);
-
-	// Flush the buffer in FPGA!!
-	for(i = 0; i < 5; i++) {
-		Sequence(SEC_F);
-	}
-
-    // Convert from last byte pos to length
-    ToSendMax++;
-
-    // Add a few more for slop
-    ToSend[ToSendMax++] = 0x00;
-	ToSend[ToSendMax++] = 0x00;
-    //ToSendMax += 2;
-}
-
-//-----------------------------------------------------------------------------
-// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4
-//-----------------------------------------------------------------------------
-static void CodeStrangeAnswer()
-{
-	int i;
-
-    ToSendReset();
-
-	// Correction bit, might be removed when not needed
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(1);  // 1
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-	ToSendStuffBit(0);
-
-	// Send startbit
-	Sequence(SEC_D);
-
-	// 0
-	Sequence(SEC_E);
-
-	// 0
-	Sequence(SEC_E);
-
-	// 1
-	Sequence(SEC_D);
-
-    // Send stopbit
-	Sequence(SEC_F);
-
-	// Flush the buffer in FPGA!!
-	for(i = 0; i < 5; i++) {
-		Sequence(SEC_F);
-	}
-
-    // Convert from last byte pos to length
-    ToSendMax++;
-
-    // Add a few more for slop
-    ToSend[ToSendMax++] = 0x00;
-	ToSend[ToSendMax++] = 0x00;
-    //ToSendMax += 2;
-}
-
-int LogTrace(const BYTE * btBytes, int iLen, int iSamples, DWORD dwParity, BOOL bReader)
-{
-  // Trace the random, i'm curious
-  rsamples += iSamples;
-  trace[traceLen++] = ((rsamples >> 0) & 0xff);
-  trace[traceLen++] = ((rsamples >> 8) & 0xff);
-  trace[traceLen++] = ((rsamples >> 16) & 0xff);
-  trace[traceLen++] = ((rsamples >> 24) & 0xff);
-  if (!bReader) {
-    trace[traceLen - 1] |= 0x80;
-  }
-  trace[traceLen++] = ((dwParity >> 0) & 0xff);
-  trace[traceLen++] = ((dwParity >> 8) & 0xff);
-  trace[traceLen++] = ((dwParity >> 16) & 0xff);
-  trace[traceLen++] = ((dwParity >> 24) & 0xff);
-  trace[traceLen++] = iLen;
-  memcpy(trace + traceLen, btBytes, iLen);
-  traceLen += iLen;
-  return (traceLen < TRACE_LENGTH);
-}
-
-//-----------------------------------------------------------------------------
-// Wait for commands from reader
-// Stop when button is pressed
-// Or return TRUE when command is captured
-//-----------------------------------------------------------------------------
-static BOOL GetIso14443aCommandFromReader(BYTE *received, int *len, int maxLen)
-{
-    // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
-    // only, since we are receiving, not transmitting).
-    // Signal field is off with the appropriate LED
-    LED_D_OFF();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
-    // Now run a `software UART' on the stream of incoming samples.
-    Uart.output = received;
-    Uart.byteCntMax = maxLen;
-    Uart.state = STATE_UNSYNCD;
-
-    for(;;) {
-        WDT_HIT();
-
-        if(BUTTON_PRESS()) return FALSE;
-
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = 0x00;
-        }
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            BYTE b = (BYTE)AT91C_BASE_SSC->SSC_RHR;
-			if(MillerDecoding((b & 0xf0) >> 4)) {
-				*len = Uart.byteCnt;
-				return TRUE;
-			}
-			if(MillerDecoding(b & 0x0f)) {
-				*len = Uart.byteCnt;
-				return TRUE;
-			}
-        }
-    }
-}
-
-//-----------------------------------------------------------------------------
-// Main loop of simulated tag: receive commands from reader, decide what
-// response to send, and send it.
-//-----------------------------------------------------------------------------
-void SimulateIso14443aTag(int tagType, int TagUid)
-{
-	// This function contains the tag emulation
-
-	// Prepare protocol messages
-    // static const BYTE cmd1[] = { 0x26 };
-//     static const BYTE response1[] = { 0x02, 0x00 }; // Says: I am Mifare 4k - original line - greg
-//
-	static const BYTE response1[] = { 0x44, 0x03 }; // Says: I am a DESFire Tag, ph33r me
-//	static const BYTE response1[] = { 0x44, 0x00 }; // Says: I am a ULTRALITE Tag, 0wn me
-
-	// UID response
-    // static const BYTE cmd2[] = { 0x93, 0x20 };
-    //static const BYTE response2[] = { 0x9a, 0xe5, 0xe4, 0x43, 0xd8 }; // original value - greg
-
-
-
-// my desfire
-    static const BYTE response2[] = { 0x88, 0x04, 0x21, 0x3f, 0x4d }; // known uid - note cascade (0x88), 2nd byte (0x04) = NXP/Phillips
-
-
-// When reader selects us during cascade1 it will send cmd3
-//BYTE response3[] = { 0x04, 0x00, 0x00 }; // SAK Select (cascade1) successful response (ULTRALITE)
-BYTE response3[] = { 0x24, 0x00, 0x00 }; // SAK Select (cascade1) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
-
-// send cascade2 2nd half of UID
-static const BYTE response2a[] = { 0x51, 0x48, 0x1d, 0x80, 0x84 }; //  uid - cascade2 - 2nd half (4 bytes) of UID+ BCCheck
-// NOTE : THE CRC on the above may be wrong as I have obfuscated the actual UID
-
-
-// When reader selects us during cascade2 it will send cmd3a
-//BYTE response3a[] = { 0x00, 0x00, 0x00 }; // SAK Select (cascade2) successful response (ULTRALITE)
-BYTE response3a[] = { 0x20, 0x00, 0x00 }; // SAK Select (cascade2) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
-
-    static const BYTE response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
-
-    BYTE *resp;
-    int respLen;
-
-    // Longest possible response will be 16 bytes + 2 CRC = 18 bytes
-	// This will need
-	//    144        data bits (18 * 8)
-	//     18        parity bits
-	//      2        Start and stop
-	//      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
-	//      1        just for the case
-	// ----------- +
-	//    166
-	//
-	// 166 bytes, since every bit that needs to be send costs us a byte
-	//
-
-
-    // Respond with card type
-    BYTE *resp1 = (((BYTE *)BigBuf) + 800);
-    int resp1Len;
-
-    // Anticollision cascade1 - respond with uid
-    BYTE *resp2 = (((BYTE *)BigBuf) + 970);
-    int resp2Len;
-
-    // Anticollision cascade2 - respond with 2nd half of uid if asked
-    // we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88
-    BYTE *resp2a = (((BYTE *)BigBuf) + 1140);
-    int resp2aLen;
-
-    // Acknowledge select - cascade 1
-    BYTE *resp3 = (((BYTE *)BigBuf) + 1310);
-    int resp3Len;
-
-    // Acknowledge select - cascade 2
-    BYTE *resp3a = (((BYTE *)BigBuf) + 1480);
-    int resp3aLen;
-
-    // Response to a read request - not implemented atm
-    BYTE *resp4 = (((BYTE *)BigBuf) + 1550);
-    int resp4Len;
-
-    // Authenticate response - nonce
-    BYTE *resp5 = (((BYTE *)BigBuf) + 1720);
-    int resp5Len;
-
-    BYTE *receivedCmd = (BYTE *)BigBuf;
-    int len;
-
-    int i;
-	int u;
-	BYTE b;
-
-	// To control where we are in the protocol
-	int order = 0;
-	int lastorder;
-
-	// Just to allow some checks
-	int happened = 0;
-	int happened2 = 0;
-
-    int cmdsRecvd = 0;
-
-	BOOL fdt_indicator;
-
-    memset(receivedCmd, 0x44, 400);
-
-	// Prepare the responses of the anticollision phase
-	// there will be not enough time to do this at the moment the reader sends it REQA
-
-	// Answer to request
-	CodeIso14443aAsTag(response1, sizeof(response1));
-    memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
-
-	// Send our UID (cascade 1)
-	CodeIso14443aAsTag(response2, sizeof(response2));
-    memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax;
-
-	// Answer to select (cascade1)
-	CodeIso14443aAsTag(response3, sizeof(response3));
-    memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax;
-
-	// Send the cascade 2 2nd part of the uid
-	CodeIso14443aAsTag(response2a, sizeof(response2a));
-    memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax;
-
-	// Answer to select (cascade 2)
-	CodeIso14443aAsTag(response3a, sizeof(response3a));
-    memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax;
-
-	// Strange answer is an example of rare message size (3 bits)
-	CodeStrangeAnswer();
-	memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
-
-	// Authentication answer (random nonce)
-	CodeIso14443aAsTag(response5, sizeof(response5));
-    memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax;
-
-    // We need to listen to the high-frequency, peak-detected path.
-    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-    FpgaSetupSsc();
-
-    cmdsRecvd = 0;
-
-    LED_A_ON();
-	for(;;) {
-
-		if(!GetIso14443aCommandFromReader(receivedCmd, &len, 100)) {
-            DbpString("button press");
-            break;
-        }
-	// doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
-        // Okay, look at the command now.
-        lastorder = order;
-		i = 1; // first byte transmitted
-        if(receivedCmd[0] == 0x26) {
-			// Received a REQUEST
-			resp = resp1; respLen = resp1Len; order = 1;
-			//DbpString("Hello request from reader:");
-		} else if(receivedCmd[0] == 0x52) {
-			// Received a WAKEUP
-			resp = resp1; respLen = resp1Len; order = 6;
-//			//DbpString("Wakeup request from reader:");
-
-		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {	// greg - cascade 1 anti-collision
-			// Received request for UID (cascade 1)
-			resp = resp2; respLen = resp2Len; order = 2;
-//			DbpString("UID (cascade 1) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] ==0x95) {	// greg - cascade 2 anti-collision
-			// Received request for UID (cascade 2)
-			resp = resp2a; respLen = resp2aLen; order = 20;
-//			DbpString("UID (cascade 2) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x93) {	// greg - cascade 1 select
-			// Received a SELECT
-			resp = resp3; respLen = resp3Len; order = 3;
-//			DbpString("Select (cascade 1) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x95) {	// greg - cascade 2 select
-			// Received a SELECT
-			resp = resp3a; respLen = resp3aLen; order = 30;
-//			DbpString("Select (cascade 2) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[0] == 0x30) {
-			// Received a READ
-			resp = resp4; respLen = resp4Len; order = 4; // Do nothing
-			DbpString("Read request from reader:");
-			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[0] == 0x50) {
-			// Received a HALT
-			resp = resp1; respLen = 0; order = 5; // Do nothing
-			DbpString("Reader requested we HALT!:");
-
-		} else if(receivedCmd[0] == 0x60) {
-			// Received an authentication request
-			resp = resp5; respLen = resp5Len; order = 7;
-			DbpString("Authenticate request from reader:");
-			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-		} else if(receivedCmd[0] == 0xE0) {
-			// Received a RATS request
-			resp = resp1; respLen = 0;order = 70;
-			DbpString("RATS request from reader:");
-			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-        } else {
-            // Never seen this command before
-			DbpString("Unknown command received from reader:");
-			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-			DbpIntegers(receivedCmd[3], receivedCmd[4], receivedCmd[5]);
-			DbpIntegers(receivedCmd[6], receivedCmd[7], receivedCmd[8]);
-
-			// Do not respond
-			resp = resp1; respLen = 0; order = 0;
-        }
-
-		// Count number of wakeups received after a halt
-		if(order == 6 && lastorder == 5) { happened++; }
-
-		// Count number of other messages after a halt
-		if(order != 6 && lastorder == 5) { happened2++; }
-
-		// Look at last parity bit to determine timing of answer
-		if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) {
-			// 1236, so correction bit needed
-			i = 0;
-		}
-
-        memset(receivedCmd, 0x44, 32);
-
-		if(cmdsRecvd > 999) {
-			DbpString("1000 commands later...");
-            break;
-        }
-		else {
-			cmdsRecvd++;
-		}
-
-        if(respLen <= 0) continue;
-
-        // Modulate Manchester
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
-        AT91C_BASE_SSC->SSC_THR = 0x00;
-        FpgaSetupSsc();
-
-		// ### Transmit the response ###
-		u = 0;
-		b = 0x00;
-		fdt_indicator = FALSE;
-        for(;;) {
-            if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-				volatile BYTE b = (BYTE)AT91C_BASE_SSC->SSC_RHR;
-                (void)b;
-            }
-            if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-				if(i > respLen) {
-					b = 0x00;
-					u++;
-				} else {
-					b = resp[i];
-					i++;
-				}
-				AT91C_BASE_SSC->SSC_THR = b;
-
-                if(u > 4) {
-                    break;
-                }
-            }
-			if(BUTTON_PRESS()) {
-			    break;
-			}
-        }
-
-    }
-
-	DbpIntegers(happened, happened2, cmdsRecvd);
-	LED_A_OFF();
-}
-
-//-----------------------------------------------------------------------------
-// Transmit the command (to the tag) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitFor14443a(const BYTE *cmd, int len, int *samples, int *wait)
-{
-    int c;
-
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-
-	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 DWORD 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 DWORD r = AT91C_BASE_SSC->SSC_RHR;
-            (void)r;
-        }
-        WDT_HIT();
-    }
-	*samples = (c + *wait) << 3;
-}
-
-//-----------------------------------------------------------------------------
-// To generate an arbitrary stream from reader
-//
-//-----------------------------------------------------------------------------
-void ArbitraryFromReader(const BYTE *cmd, int parity, int len)
-{
-	int i;
-	int j;
-	int last;
-    BYTE b;
-
-	ToSendReset();
-
-	// Start of Communication (Seq. Z)
-	Sequence(SEC_Z);
-	last = 0;
-
-	for(i = 0; i < len; i++) {
-        // Data bits
-        b = cmd[i];
-		for(j = 0; j < 8; j++) {
-			if(b & 1) {
-				// Sequence X
-				Sequence(SEC_X);
-				last = 1;
-			} else {
-				if(last == 0) {
-					// Sequence Z
-					Sequence(SEC_Z);
-				}
-				else {
-					// Sequence Y
-					Sequence(SEC_Y);
-					last = 0;
-				}
-			}
-			b >>= 1;
-
-		}
-
-		// Predefined parity bit, the flipper flips when needed, because of flips in byte sent
-		if(((parity >> (len - i - 1)) & 1)) {
-			// Sequence X
-			Sequence(SEC_X);
-			last = 1;
-		} else {
-			if(last == 0) {
-				// Sequence Z
-				Sequence(SEC_Z);
-			}
-			else {
-				// Sequence Y
-				Sequence(SEC_Y);
-				last = 0;
-			}
-		}
-	}
-
-	// End of Communication
-	if(last == 0) {
-		// Sequence Z
-		Sequence(SEC_Z);
-	}
-	else {
-		// Sequence Y
-		Sequence(SEC_Y);
-		last = 0;
-	}
-	// Sequence Y
-	Sequence(SEC_Y);
-
-	// Just to be sure!
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-
-    // Convert from last character reference to length
-    ToSendMax++;
-}
-
-//-----------------------------------------------------------------------------
-// Code a 7-bit command without parity bit
-// This is especially for 0x26 and 0x52 (REQA and WUPA)
-//-----------------------------------------------------------------------------
-void ShortFrameFromReader(const BYTE *cmd)
-{
-	int j;
-	int last;
-    BYTE b;
-
-	ToSendReset();
-
-	// Start of Communication (Seq. Z)
-	Sequence(SEC_Z);
-	last = 0;
-
-	b = cmd[0];
-	for(j = 0; j < 7; j++) {
-		if(b & 1) {
-			// Sequence X
-			Sequence(SEC_X);
-			last = 1;
-		} else {
-			if(last == 0) {
-				// Sequence Z
-				Sequence(SEC_Z);
-			}
-			else {
-				// Sequence Y
-				Sequence(SEC_Y);
-				last = 0;
-			}
-		}
-		b >>= 1;
-	}
-
-	// End of Communication
-	if(last == 0) {
-		// Sequence Z
-		Sequence(SEC_Z);
-	}
-	else {
-		// Sequence Y
-		Sequence(SEC_Y);
-		last = 0;
-	}
-	// Sequence Y
-	Sequence(SEC_Y);
-
-	// Just to be sure!
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-
-    // Convert from last character reference to length
-    ToSendMax++;
-}
-
-//-----------------------------------------------------------------------------
-// Prepare reader command to send to FPGA
-//
-//-----------------------------------------------------------------------------
-void CodeIso14443aAsReader(const BYTE *cmd, int len)
-{
-    int i, j;
-	int last;
-	int oddparity;
-    BYTE b;
-
-    ToSendReset();
-
-	// Start of Communication (Seq. Z)
-	Sequence(SEC_Z);
-	last = 0;
-
-	for(i = 0; i < len; i++) {
-        // Data bits
-        b = cmd[i];
-        oddparity = 0x01;
-        for(j = 0; j < 8; j++) {
-            oddparity ^= (b & 1);
-            if(b & 1) {
-				// Sequence X
-				Sequence(SEC_X);
-				last = 1;
-            } else {
-                if(last == 0) {
-					// Sequence Z
-					Sequence(SEC_Z);
-				}
-				else {
-					// Sequence Y
-					Sequence(SEC_Y);
-					last = 0;
-				}
-            }
-            b >>= 1;
-        }
-
-		// Parity bit
-		if(oddparity) {
-			// Sequence X
-			Sequence(SEC_X);
-			last = 1;
-		} else {
-			if(last == 0) {
-				// Sequence Z
-				Sequence(SEC_Z);
-			}
-			else {
-				// Sequence Y
-				Sequence(SEC_Y);
-				last = 0;
-			}
-		}
-    }
-
-	// End of Communication
-	if(last == 0) {
-		// Sequence Z
-		Sequence(SEC_Z);
-	}
-	else {
-		// Sequence Y
-		Sequence(SEC_Y);
-		last = 0;
-	}
-	// Sequence Y
-	Sequence(SEC_Y);
-
-	// Just to be sure!
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-	Sequence(SEC_Y);
-
-    // Convert from last character reference to length
-    ToSendMax++;
-}
-
-
-//-----------------------------------------------------------------------------
-// Wait a certain time for tag response
-//  If a response is captured return TRUE
-//  If it takes to long return FALSE
-//-----------------------------------------------------------------------------
-static BOOL GetIso14443aAnswerFromTag(BYTE *receivedResponse, int maxLen, int *samples, int *elapsed) //BYTE *buffer
-{
-	// buffer needs to be 512 bytes
-	int c;
-
-	// Set FPGA mode to "reader listen mode", no modulation (listen
-    // only, since we are receiving, not transmitting).
-    // Signal field is on with the appropriate LED
-    LED_D_ON();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
-
-    // Now get the answer from the card
-    Demod.output = receivedResponse;
-    Demod.len = 0;
-    Demod.state = DEMOD_UNSYNCD;
-
-	BYTE b;
-	*elapsed = 0;
-
-	c = 0;
-	for(;;) {
-        WDT_HIT();
-
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
-			(*elapsed)++;
-        }
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			if(c < 512) { c++; } else { return FALSE; }
-            b = (BYTE)AT91C_BASE_SSC->SSC_RHR;
-			if(ManchesterDecoding((b & 0xf0) >> 4)) {
-				*samples = ((c - 1) << 3) + 4;
-				return TRUE;
-			}
-			if(ManchesterDecoding(b & 0x0f)) {
-				*samples = c << 3;
-				return TRUE;
-			}
-        }
-    }
-}
-
-
-
-//-----------------------------------------------------------------------------
-// Read an ISO 14443a tag. Send out commands and store answers.
-//
-//-----------------------------------------------------------------------------
-void ReaderIso14443a(DWORD parameter)
-{
-	// Anticollision
-	static const BYTE cmd1[]       = { 0x52 }; // or 0x26
-	static const BYTE cmd2[]       = { 0x93,0x20 };
-	// UID = 0x2a,0x69,0x8d,0x43,0x8d, last two bytes are CRC bytes
-	BYTE cmd3[] = { 0x93,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 };
-
-	// For Ultralight add an extra anticollission layer -> 95 20 and then 95 70
-
-	// greg - here we will add our cascade level 2 anticolission and select functions to deal with ultralight 		// and 7-byte UIDs in generall...
-	BYTE cmd4[] = {0x95,0x20};	// ask for cascade 2 select
-	// 95 20
-	//BYTE cmd3a[] = { 0x95,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 };
-	// 95 70
-
-	// cascade 2 select
-	BYTE cmd5[] = { 0x95,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 };
-
-
-	// RATS (request for answer to select)
-	//BYTE cmd6[] = { 0xe0,0x50,0xbc,0xa5 };  // original RATS
-	BYTE cmd6[] = { 0xe0,0x21,0xb2,0xc7 };  // Desfire RATS
-
-	// Mifare AUTH
-	BYTE cmd7[] = { 0x60, 0x00, 0x00, 0x00 };
-
-	int reqaddr = 2024;					// was 2024 - tied to other size changes
-	int reqsize = 60;
-
-	BYTE *req1 = (((BYTE *)BigBuf) + reqaddr);
-    int req1Len;
-
-    BYTE *req2 = (((BYTE *)BigBuf) + reqaddr + reqsize);
-    int req2Len;
-
-    BYTE *req3 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 2));
-    int req3Len;
-
-// greg added req 4 & 5 to deal with cascade 2 section
-    BYTE *req4 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 3));
-    int req4Len;
-
-    BYTE *req5 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 4));
-    int req5Len;
-
-    BYTE *req6 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 5));
-    int req6Len;
-
-    BYTE *req7 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 6));
-    int req7Len;
-
-	BYTE *receivedAnswer = (((BYTE *)BigBuf) + 3560);	// was 3560 - tied to other size changes
-
-	//BYTE *trace = (BYTE *)BigBuf;
-	//int traceLen = 0;
-	//int rsamples = 0;
-  traceLen = 0;
-
-	memset(trace, 0x44, 2000);				// was 2000 - tied to oter size chnages
-	// setting it to 3000 causes no tag responses to be detected (2900 is ok)
-	// setting it to 1000 causes no tag responses to be detected
-
-	// Prepare some commands!
-    ShortFrameFromReader(cmd1);
-    memcpy(req1, ToSend, ToSendMax); req1Len = ToSendMax;
-
-	CodeIso14443aAsReader(cmd2, sizeof(cmd2));
-    memcpy(req2, ToSend, ToSendMax); req2Len = ToSendMax;
-
-	CodeIso14443aAsReader(cmd3, sizeof(cmd3));
-    memcpy(req3, ToSend, ToSendMax); req3Len = ToSendMax;
-
-
-	CodeIso14443aAsReader(cmd4, sizeof(cmd4));		// 4 is cascade 2 request
-    memcpy(req4, ToSend, ToSendMax); req4Len = ToSendMax;
-
-
-	CodeIso14443aAsReader(cmd5, sizeof(cmd5));	// 5 is cascade 2 select
-    memcpy(req5, ToSend, ToSendMax); req5Len = ToSendMax;
-
-
-	CodeIso14443aAsReader(cmd6, sizeof(cmd6));
-    memcpy(req6, ToSend, ToSendMax); req6Len = ToSendMax;
-
-	// Setup SSC
-	FpgaSetupSsc();
-
-	// Start from off (no field generated)
-    // Signal field is off with the appropriate LED
-    LED_D_OFF();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    SpinDelay(200);
-
-    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-    FpgaSetupSsc();
-
-	// Now give it time to spin up.
-    // Signal field is on with the appropriate LED
-    LED_D_ON();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-	SpinDelay(200);
-
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
-
-	int samples = 0;
-	int tsamples = 0;
-	int wait = 0;
-	int elapsed = 0;
-
-	while(1) {
-		// Send WUPA (or REQA)
-		TransmitFor14443a(req1, req1Len, &tsamples, &wait);
-
-    // Store reader command in buffer
-    if (!LogTrace(cmd1,1,0,GetParity(cmd1,1),TRUE)) break;
-    
-    // Test if the action was cancelled
-    if(BUTTON_PRESS()) {
-      break;
-    }
-    
-		if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-    
-    // Log the ATQA
-    if (!LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE)) break;
-
-    // Store reader command in buffer
-    if (!LogTrace(cmd2,2,0,GetParity(cmd2,2),TRUE)) break;
-    TransmitFor14443a(req2, req2Len, &samples, &wait);
-
-		if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-
-    // Log the uid
-    if (!LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE)) break;
-    
-		// Construct SELECT UID command
-		// First copy the 5 bytes (Mifare Classic) after the 93 70
-		memcpy(cmd3+2,receivedAnswer,5);
-		// Secondly compute the two CRC bytes at the end
-		ComputeCrc14443(CRC_14443_A, cmd3, 7, &cmd3[7], &cmd3[8]);
-
-		// Store reader command in buffer
-    if (!LogTrace(cmd3,9,0,GetParity(cmd5,9),TRUE)) break;
-		
-		CodeIso14443aAsReader(cmd3, sizeof(cmd3));
-		memcpy(req3, ToSend, ToSendMax); req3Len = ToSendMax;
-
-		// Select the card
-		TransmitFor14443a(req3, req3Len, &samples, &wait);
-		if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-
-    // Log the SAK
-    if (!LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE)) break;
-
-    // OK we have selected at least at cascade 1, lets see if first byte of UID was 0x88 in
-    // which case we need to make a cascade 2 request and select - this is a long UID
-		if (receivedAnswer[0] == 0x88)
-		{
-      // Do cascade level 2 stuff
-      ///////////////////////////////////////////////////////////////////
-      // First issue a '95 20' identify request
-      // Ask for card UID (part 2)
-      TransmitFor14443a(req4, req4Len, &tsamples, &wait);
-
-      // Store reader command in buffer
-      if (!LogTrace(cmd4,2,0,GetParity(cmd4,2),TRUE)) break;
-
-      if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-
-      //////////////////////////////////////////////////////////////////
-      // Then Construct SELECT UID (cascasde 2) command
-      DbpString("Just about to copy the UID out of the cascade 2 id req");
-      // First copy the 5 bytes (Mifare Classic) after the 95 70
-      memcpy(cmd5+2,receivedAnswer,5);
-      // Secondly compute the two CRC bytes at the end
-      ComputeCrc14443(CRC_14443_A, cmd4, 7, &cmd5[7], &cmd5[8]);
-
-      // Store reader command in buffer
-      if (!LogTrace(cmd5,9,0,GetParity(cmd5,9),TRUE)) break;
-
-      CodeIso14443aAsReader(cmd5, sizeof(cmd5));
-      memcpy(req5, ToSend, ToSendMax); req5Len = ToSendMax;
-      
-      // Select the card
-      TransmitFor14443a(req4, req4Len, &samples, &wait);
-      if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-      
-      // Log the SAK
-      if (!LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE)) break;
-		}
-
-		// Secondly compute the two CRC bytes at the end
-		ComputeCrc14443(CRC_14443_A, cmd7, 2, &cmd7[2], &cmd7[3]);
-		CodeIso14443aAsReader(cmd7, sizeof(cmd7));
-		memcpy(req7, ToSend, ToSendMax); req7Len = ToSendMax;
-
-		// Send authentication request (Mifare Classic)
-		TransmitFor14443a(req7, req7Len, &samples, &wait);
-    // Store reader command in buffer
-    if (!LogTrace(cmd7,4,0,GetParity(cmd7,4),TRUE)) break;
-
-		if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) continue;
-
-    // We received probably a random, continue and trace!
-    if (!LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE)) break;
-	}
-
-  // Thats it...
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	LEDsoff();
-	DbpIntegers(rsamples, 0xCC, 0xCC);
-	DbpString("ready..");
-}
+//-----------------------------------------------------------------------------
+// Merlok - June 2011, 2012
+// Gerhard de Koning Gans - May 2008
+// Hagen Fritsch - June 2010
+//
+// 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 14443 type A.
+//-----------------------------------------------------------------------------
+
+#include "proxmark3.h"
+#include "apps.h"
+#include "util.h"
+#include "string.h"
+#include "cmd.h"
+
+#include "iso14443crc.h"
+#include "iso14443a.h"
+#include "crapto1.h"
+#include "mifareutil.h"
+
+static uint32_t iso14a_timeout;
+uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
+int rsamples = 0;
+int traceLen = 0;
+int tracing = TRUE;
+uint8_t trigger = 0;
+// the block number for the ISO14443-4 PCB
+static uint8_t iso14_pcb_blocknum = 0;
+
+//
+// ISO14443 timing:
+//
+// minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
+#define REQUEST_GUARD_TIME (7000/16 + 1)
+// minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles 
+#define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1) 
+// bool LastCommandWasRequest = FALSE;
+
+//
+// Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
+//
+// When the PM acts as reader and is receiving tag data, it takes
+// 3 ticks delay in the AD converter
+// 16 ticks until the modulation detector completes and sets curbit
+// 8 ticks until bit_to_arm is assigned from curbit
+// 8*16 ticks for the transfer from FPGA to ARM
+// 4*16 ticks until we measure the time
+// - 8*16 ticks because we measure the time of the previous transfer 
+#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16) 
+
+// When the PM acts as a reader and is sending, it takes
+// 4*16 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks until the first transfer starts
+// 8 ticks later the FPGA samples the data
+// 1 tick to assign mod_sig_coil
+#define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
+
+// When the PM acts as tag and is receiving it takes
+// 2 ticks delay in the RF part (for the first falling edge),
+// 3 ticks for the A/D conversion,
+// 8 ticks on average until the start of the SSC transfer,
+// 8 ticks until the SSC samples the first data
+// 7*16 ticks to complete the transfer from FPGA to ARM
+// 8 ticks until the next ssp_clk rising edge
+// 4*16 ticks until we measure the time 
+// - 8*16 ticks because we measure the time of the previous transfer 
+#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
+ 
+// The FPGA will report its internal sending delay in
+uint16_t FpgaSendQueueDelay;
+// the 5 first bits are the number of bits buffered in mod_sig_buf
+// the last three bits are the remaining ticks/2 after the mod_sig_buf shift
+#define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
+
+// When the PM acts as tag and is sending, it takes
+// 4*16 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks until the first transfer starts
+// 8 ticks later the FPGA samples the data
+// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
+// + 1 tick to assign mod_sig_coil
+#define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
+
+// When the PM acts as sniffer and is receiving tag data, it takes
+// 3 ticks A/D conversion
+// 14 ticks to complete the modulation detection
+// 8 ticks (on average) until the result is stored in to_arm
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8) 
+ 
+// When the PM acts as sniffer and is receiving reader data, it takes
+// 2 ticks delay in analogue RF receiver (for the falling edge of the 
+// start bit, which marks the start of the communication)
+// 3 ticks A/D conversion
+// 8 ticks on average until the data is stored in to_arm.
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8) 
+
+//variables used for timing purposes:
+//these are in ssp_clk cycles:
+uint32_t NextTransferTime;
+uint32_t LastTimeProxToAirStart;
+uint32_t LastProxToAirDuration;
+
+
+
+// CARD TO READER - manchester
+// Sequence D: 11110000 modulation with subcarrier during first half
+// Sequence E: 00001111 modulation with subcarrier during second half
+// Sequence F: 00000000 no modulation with subcarrier
+// READER TO CARD - miller
+// Sequence X: 00001100 drop after half a period
+// Sequence Y: 00000000 no drop
+// Sequence Z: 11000000 drop at start
+#define	SEC_D 0xf0
+#define	SEC_E 0x0f
+#define	SEC_F 0x00
+#define	SEC_X 0x0c
+#define	SEC_Y 0x00
+#define	SEC_Z 0xc0
+
+const uint8_t OddByteParity[256] = {
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
+  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
+};
+
+
+void iso14a_set_trigger(bool enable) {
+	trigger = enable;
+}
+
+void iso14a_clear_trace() {
+	memset(trace, 0x44, TRACE_SIZE);
+	traceLen = 0;
+}
+
+void iso14a_set_tracing(bool enable) {
+	tracing = enable;
+}
+
+void iso14a_set_timeout(uint32_t timeout) {
+	iso14a_timeout = timeout;
+}
+
+//-----------------------------------------------------------------------------
+// Generate the parity value for a byte sequence
+//
+//-----------------------------------------------------------------------------
+byte_t oddparity (const byte_t bt)
+{
+	return OddByteParity[bt];
+}
+
+uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
+{
+	int i;
+	uint32_t dwPar = 0;
+
+	// Generate the parity bits
+	for (i = 0; i < iLen; i++) {
+		// and save them to a 32Bit word
+		dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
+	}
+	return dwPar;
+}
+
+void AppendCrc14443a(uint8_t* data, int len)
+{
+	ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
+}
+
+// The function LogTrace() is also used by the iClass implementation in iClass.c
+bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp, uint32_t dwParity, bool readerToTag)
+{
+	if (!tracing) return FALSE;
+	// Return when trace is full
+	if (traceLen + sizeof(timestamp) + sizeof(dwParity) + iLen >= TRACE_SIZE) {
+		tracing = FALSE;	// don't trace any more
+		return FALSE;
+	}
+	
+	// Trace the random, i'm curious
+	trace[traceLen++] = ((timestamp >> 0) & 0xff);
+	trace[traceLen++] = ((timestamp >> 8) & 0xff);
+	trace[traceLen++] = ((timestamp >> 16) & 0xff);
+	trace[traceLen++] = ((timestamp >> 24) & 0xff);
+
+	if (!readerToTag) {
+		trace[traceLen - 1] |= 0x80;
+	}
+	trace[traceLen++] = ((dwParity >> 0) & 0xff);
+	trace[traceLen++] = ((dwParity >> 8) & 0xff);
+	trace[traceLen++] = ((dwParity >> 16) & 0xff);
+	trace[traceLen++] = ((dwParity >> 24) & 0xff);
+	trace[traceLen++] = iLen;
+	if (btBytes != NULL && iLen != 0) {
+		memcpy(trace + traceLen, btBytes, iLen);
+	}
+	traceLen += iLen;
+	return TRUE;
+}
+
+//=============================================================================
+// ISO 14443 Type A - Miller decoder
+//=============================================================================
+// Basics:
+// This decoder is used when the PM3 acts as a tag.
+// The reader will generate "pauses" by temporarily switching of the field. 
+// At the PM3 antenna we will therefore measure a modulated antenna voltage. 
+// The FPGA does a comparison with a threshold and would deliver e.g.:
+// ........  1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1  .......
+// The Miller decoder needs to identify the following sequences:
+// 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: 	pause at beginning - Sequence Z ("start of communication" or a "0")
+// 8 ticks without a modulation: 									no pause - Sequence Y (a "0" or "end of communication" or "no information")
+// 4 ticks unmodulated followed by 2 (or 3) ticks pause:			pause in second half - Sequence X (a "1")
+// Note 1: the bitstream may start at any time. We therefore need to sync.
+// Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
+//-----------------------------------------------------------------------------
+static tUart Uart;
+
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept two or three consecutive "0" in any position with the rest "1"
+const bool Mod_Miller_LUT[] = {
+	TRUE,  TRUE,  FALSE, TRUE,  FALSE, FALSE, FALSE, FALSE,
+	TRUE,  TRUE,  FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE
+};
+#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
+#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
+
+void UartReset()
+{
+	Uart.state = STATE_UNSYNCD;
+	Uart.bitCount = 0;
+	Uart.len = 0;						// number of decoded data bytes
+	Uart.shiftReg = 0;					// shiftreg to hold decoded data bits
+	Uart.parityBits = 0;				// 
+	Uart.twoBits = 0x0000;	 			// buffer for 2 Bits
+	Uart.highCnt = 0;
+	Uart.startTime = 0;
+	Uart.endTime = 0;
+}
+
+
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
+{
+
+	Uart.twoBits = (Uart.twoBits << 8) | bit;
+	
+	if (Uart.state == STATE_UNSYNCD) {												// not yet synced
+		if (Uart.highCnt < 7) {													// wait for a stable unmodulated signal
+			if (Uart.twoBits == 0xffff) {
+				Uart.highCnt++;
+			} else {
+				Uart.highCnt = 0;
+			}
+		} else {	
+			Uart.syncBit = 0xFFFF; // not set
+			// look for 00xx1111 (the start bit)
+			if 		((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7; 
+			else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
+			else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
+			else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
+			else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
+			else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
+			else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
+			else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
+			if (Uart.syncBit != 0xFFFF) {
+				Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+				Uart.startTime -= Uart.syncBit;
+				Uart.endTime = Uart.startTime;
+				Uart.state = STATE_START_OF_COMMUNICATION;
+			}
+		}
+
+	} else {
+
+		if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {			
+			if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) {		// Modulation in both halves - error
+				UartReset();
+				Uart.highCnt = 6;
+			} else {															// Modulation in first half = Sequence Z = logic "0"
+				if (Uart.state == STATE_MILLER_X) {								// error - must not follow after X
+					UartReset();
+					Uart.highCnt = 6;
+				} else {
+					Uart.bitCount++;
+					Uart.shiftReg = (Uart.shiftReg >> 1);						// add a 0 to the shiftreg
+					Uart.state = STATE_MILLER_Z;
+					Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
+					if(Uart.bitCount >= 9) {									// if we decoded a full byte (including parity)
+						Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+						Uart.parityBits <<= 1;									// make room for the parity bit
+						Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);		// store parity bit
+						Uart.bitCount = 0;
+						Uart.shiftReg = 0;
+					}
+				}
+			}
+		} else {
+			if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) {		// Modulation second half = Sequence X = logic "1"
+				Uart.bitCount++;
+				Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;					// add a 1 to the shiftreg
+				Uart.state = STATE_MILLER_X;
+				Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
+				if(Uart.bitCount >= 9) {										// if we decoded a full byte (including parity)
+					Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+					Uart.parityBits <<= 1;										// make room for the new parity bit
+					Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); 			// store parity bit
+					Uart.bitCount = 0;
+					Uart.shiftReg = 0;
+				}
+			} else {															// no modulation in both halves - Sequence Y
+				if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {	// Y after logic "0" - End of Communication
+					Uart.state = STATE_UNSYNCD;
+					if(Uart.len == 0 && Uart.bitCount > 0) {										// if we decoded some bits
+						Uart.shiftReg >>= (9 - Uart.bitCount);					// add them to the output
+						Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+						Uart.parityBits <<= 1;									// no parity bit - add "0"
+						Uart.bitCount--;										// last "0" was part of the EOC sequence
+					}
+					return TRUE;
+				}
+				if (Uart.state == STATE_START_OF_COMMUNICATION) {				// error - must not follow directly after SOC
+					UartReset();
+					Uart.highCnt = 6;
+				} else {														// a logic "0"
+					Uart.bitCount++;
+					Uart.shiftReg = (Uart.shiftReg >> 1);						// add a 0 to the shiftreg
+					Uart.state = STATE_MILLER_Y;
+					if(Uart.bitCount >= 9) {									// if we decoded a full byte (including parity)
+						Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+						Uart.parityBits <<= 1;									// make room for the parity bit
+						Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); 		// store parity bit
+						Uart.bitCount = 0;
+						Uart.shiftReg = 0;
+					}
+				}
+			}
+		}
+			
+	} 
+
+    return FALSE;	// not finished yet, need more data
+}
+
+
+
+//=============================================================================
+// ISO 14443 Type A - Manchester decoder
+//=============================================================================
+// Basics:
+// This decoder is used when the PM3 acts as a reader.
+// The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
+// at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
+// ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .......
+// The Manchester decoder needs to identify the following sequences:
+// 4 ticks modulated followed by 4 ticks unmodulated: 	Sequence D = 1 (also used as "start of communication")
+// 4 ticks unmodulated followed by 4 ticks modulated: 	Sequence E = 0
+// 8 ticks unmodulated:									Sequence F = end of communication
+// 8 ticks modulated:									A collision. Save the collision position and treat as Sequence D
+// Note 1: the bitstream may start at any time. We therefore need to sync.
+// Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
+static tDemod Demod;
+
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept three or four "1" in any position
+const bool Mod_Manchester_LUT[] = {
+	FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
+	FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
+};
+
+#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
+#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
+
+
+void DemodReset()
+{
+	Demod.state = DEMOD_UNSYNCD;
+	Demod.len = 0;						// number of decoded data bytes
+	Demod.shiftReg = 0;					// shiftreg to hold decoded data bits
+	Demod.parityBits = 0;				// 
+	Demod.collisionPos = 0;				// Position of collision bit
+	Demod.twoBits = 0xffff;				// buffer for 2 Bits
+	Demod.highCnt = 0;
+	Demod.startTime = 0;
+	Demod.endTime = 0;
+}
+
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
+{
+
+	Demod.twoBits = (Demod.twoBits << 8) | bit;
+	
+	if (Demod.state == DEMOD_UNSYNCD) {
+
+		if (Demod.highCnt < 2) {											// wait for a stable unmodulated signal
+			if (Demod.twoBits == 0x0000) {
+				Demod.highCnt++;
+			} else {
+				Demod.highCnt = 0;
+			}
+		} else {
+			Demod.syncBit = 0xFFFF;			// not set
+			if 		((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7; 
+			else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
+			else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
+			else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
+			else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
+			else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
+			else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
+			else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
+			if (Demod.syncBit != 0xFFFF) {
+				Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+				Demod.startTime -= Demod.syncBit;
+				Demod.bitCount = offset;			// number of decoded data bits
+				Demod.state = DEMOD_MANCHESTER_DATA;
+			}
+		}
+
+	} else {
+
+		if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {		// modulation in first half
+			if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {	// ... and in second half = collision
+				if (!Demod.collisionPos) {
+					Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
+				}
+			}															// modulation in first half only - Sequence D = 1
+			Demod.bitCount++;
+			Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;				// in both cases, add a 1 to the shiftreg
+			if(Demod.bitCount == 9) {									// if we decoded a full byte (including parity)
+				Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+				Demod.parityBits <<= 1;									// make room for the parity bit
+				Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); 	// store parity bit
+				Demod.bitCount = 0;
+				Demod.shiftReg = 0;
+			}
+			Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
+		} else {														// no modulation in first half
+			if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {	// and modulation in second half = Sequence E = 0
+				Demod.bitCount++;
+				Demod.shiftReg = (Demod.shiftReg >> 1);					// add a 0 to the shiftreg
+				if(Demod.bitCount >= 9) {								// if we decoded a full byte (including parity)
+					Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+					Demod.parityBits <<= 1;								// make room for the new parity bit
+					Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
+					Demod.bitCount = 0;
+					Demod.shiftReg = 0;
+				}
+				Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
+			} else {													// no modulation in both halves - End of communication
+				if (Demod.len > 0 || Demod.bitCount > 0) {				// received something
+					if(Demod.bitCount > 0) {							// if we decoded bits
+						Demod.shiftReg >>= (9 - Demod.bitCount);		// add the remaining decoded bits to the output
+						Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
+						// No parity bit, so just shift a 0
+						Demod.parityBits <<= 1;
+					}
+					return TRUE;										// we are finished with decoding the raw data sequence
+				} else { 												// nothing received. Start over
+					DemodReset();
+				}
+			}
+		}
+			
+	} 
+
+    return FALSE;	// not finished yet, need more data
+}
+
+//=============================================================================
+// Finally, a `sniffer' for ISO 14443 Type A
+// Both sides of communication!
+//=============================================================================
+
+//-----------------------------------------------------------------------------
+// Record the sequence of commands sent by the reader to the tag, with
+// triggering so that we start recording at the point that the tag is moved
+// near the reader.
+//-----------------------------------------------------------------------------
+void RAMFUNC SnoopIso14443a(uint8_t param) {
+	// param:
+	// bit 0 - trigger from first card answer
+	// bit 1 - trigger from first reader 7-bit request
+	
+	LEDsoff();
+	// init trace buffer
+	iso14a_clear_trace();
+
+	// We won't start recording the frames that we acquire until we trigger;
+	// a good trigger condition to get started is probably when we see a
+	// response from the tag.
+	// triggered == FALSE -- to wait first for card
+	bool triggered = !(param & 0x03); 
+	
+	// The command (reader -> tag) that we're receiving.
+	// The length of a received command will in most cases be no more than 18 bytes.
+	// So 32 should be enough!
+	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	// The response (tag -> reader) that we're receiving.
+	uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
+
+	// As we receive stuff, we copy it from receivedCmd or receivedResponse
+	// into trace, along with its length and other annotations.
+	//uint8_t *trace = (uint8_t *)BigBuf;
+	
+	// The DMA buffer, used to stream samples from the FPGA
+	uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
+	uint8_t *data = dmaBuf;
+	uint8_t previous_data = 0;
+	int maxDataLen = 0;
+	int dataLen = 0;
+	bool TagIsActive = FALSE;
+	bool ReaderIsActive = FALSE;
+	
+	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
+	// Set up the demodulator for tag -> reader responses.
+	Demod.output = receivedResponse;
+
+	// Set up the demodulator for the reader -> tag commands
+	Uart.output = receivedCmd;
+
+	// Setup and start DMA.
+	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
+	
+	// And now we loop, receiving samples.
+	for(uint32_t rsamples = 0; TRUE; ) {
+
+		if(BUTTON_PRESS()) {
+			DbpString("cancelled by button");
+			break;
+		}
+
+		LED_A_ON();
+		WDT_HIT();
+
+		int register readBufDataP = data - dmaBuf;
+		int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
+		if (readBufDataP <= dmaBufDataP){
+			dataLen = dmaBufDataP - readBufDataP;
+		} else {
+			dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
+		}
+		// test for length of buffer
+		if(dataLen > maxDataLen) {
+			maxDataLen = dataLen;
+			if(dataLen > 400) {
+				Dbprintf("blew circular buffer! dataLen=%d", dataLen);
+				break;
+			}
+		}
+		if(dataLen < 1) continue;
+
+		// primary buffer was stopped( <-- we lost data!
+		if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+			AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+			Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
+		}
+		// secondary buffer sets as primary, secondary buffer was stopped
+		if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+		}
+
+		LED_A_OFF();
+		
+		if (rsamples & 0x01) {				// Need two samples to feed Miller and Manchester-Decoder
+
+			if(!TagIsActive) {		// no need to try decoding reader data if the tag is sending
+				uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+				if (MillerDecoding(readerdata, (rsamples-1)*4)) {
+					LED_C_ON();
+
+					// check - if there is a short 7bit request from reader
+					if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
+
+					if(triggered) {
+						if (!LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.parityBits, TRUE)) break;
+						if (!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
+					}
+					/* And ready to receive another command. */
+					UartReset();
+					/* And also reset the demod code, which might have been */
+					/* false-triggered by the commands from the reader. */
+					DemodReset();
+					LED_B_OFF();
+				}
+				ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+			}
+
+			if(!ReaderIsActive) {		// no need to try decoding tag data if the reader is sending - and we cannot afford the time
+				uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+				if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
+					LED_B_ON();
+
+					if (!LogTrace(receivedResponse, Demod.len, Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.parityBits, FALSE)) break;
+					if (!LogTrace(NULL, 0, Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, 0, FALSE)) break;
+
+					if ((!triggered) && (param & 0x01)) triggered = TRUE;
+
+					// And ready to receive another response.
+					DemodReset();
+					LED_C_OFF();
+				} 
+				TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+			}
+		}
+
+		previous_data = *data;
+		rsamples++;
+		data++;
+		if(data == dmaBuf + DMA_BUFFER_SIZE) {
+			data = dmaBuf;
+		}
+	} // main cycle
+
+	DbpString("COMMAND FINISHED");
+
+	FpgaDisableSscDma();
+	Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
+	Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
+	LEDsoff();
+}
+
+//-----------------------------------------------------------------------------
+// Prepare tag messages
+//-----------------------------------------------------------------------------
+static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
+{
+	int i;
+
+	ToSendReset();
+
+	// Correction bit, might be removed when not needed
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(1);  // 1
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	
+	// Send startbit
+	ToSend[++ToSendMax] = SEC_D;
+	LastProxToAirDuration = 8 * ToSendMax - 4;
+
+	for(i = 0; i < len; i++) {
+		int j;
+		uint8_t b = cmd[i];
+
+		// Data bits
+		for(j = 0; j < 8; j++) {
+			if(b & 1) {
+				ToSend[++ToSendMax] = SEC_D;
+			} else {
+				ToSend[++ToSendMax] = SEC_E;
+			}
+			b >>= 1;
+		}
+
+		// Get the parity bit
+		if ((dwParity >> i) & 0x01) {
+			ToSend[++ToSendMax] = SEC_D;
+			LastProxToAirDuration = 8 * ToSendMax - 4;
+		} else {
+			ToSend[++ToSendMax] = SEC_E;
+			LastProxToAirDuration = 8 * ToSendMax;
+		}
+	}
+
+	// Send stopbit
+	ToSend[++ToSendMax] = SEC_F;
+
+	// Convert from last byte pos to length
+	ToSendMax++;
+}
+
+static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
+	CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
+}
+
+
+static void Code4bitAnswerAsTag(uint8_t cmd)
+{
+	int i;
+
+	ToSendReset();
+
+	// Correction bit, might be removed when not needed
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(1);  // 1
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+
+	// Send startbit
+	ToSend[++ToSendMax] = SEC_D;
+
+	uint8_t b = cmd;
+	for(i = 0; i < 4; i++) {
+		if(b & 1) {
+			ToSend[++ToSendMax] = SEC_D;
+			LastProxToAirDuration = 8 * ToSendMax - 4;
+		} else {
+			ToSend[++ToSendMax] = SEC_E;
+			LastProxToAirDuration = 8 * ToSendMax;
+		}
+		b >>= 1;
+	}
+
+	// Send stopbit
+	ToSend[++ToSendMax] = SEC_F;
+
+	// Convert from last byte pos to length
+	ToSendMax++;
+}
+
+//-----------------------------------------------------------------------------
+// Wait for commands from reader
+// Stop when button is pressed
+// Or return TRUE when command is captured
+//-----------------------------------------------------------------------------
+static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
+{
+    // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
+    // only, since we are receiving, not transmitting).
+    // Signal field is off with the appropriate LED
+    LED_D_OFF();
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+    // Now run a `software UART' on the stream of incoming samples.
+	UartReset();
+    Uart.output = received;
+
+	// clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+
+    for(;;) {
+        WDT_HIT();
+
+        if(BUTTON_PRESS()) return FALSE;
+		
+        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+            b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			if(MillerDecoding(b, 0)) {
+				*len = Uart.len;
+				return TRUE;
+			}
+ 		}
+    }
+}
+
+static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded);
+int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
+int EmSend4bit(uint8_t resp);
+int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
+int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
+int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded);
+int EmSendCmd(uint8_t *resp, int respLen);
+int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
+bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
+				 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity);
+
+static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+
+typedef struct {
+  uint8_t* response;
+  size_t   response_n;
+  uint8_t* modulation;
+  size_t   modulation_n;
+  uint32_t ProxToAirDuration;
+} tag_response_info_t;
+
+void reset_free_buffer() {
+  free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+}
+
+bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
+	// Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
+	// This will need the following byte array for a modulation sequence
+	//    144        data bits (18 * 8)
+	//     18        parity bits
+	//      2        Start and stop
+	//      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
+	//      1        just for the case
+	// ----------- +
+	//    166 bytes, since every bit that needs to be send costs us a byte
+	//
+  
+  // Prepare the tag modulation bits from the message
+  CodeIso14443aAsTag(response_info->response,response_info->response_n);
+  
+  // Make sure we do not exceed the free buffer space
+  if (ToSendMax > max_buffer_size) {
+    Dbprintf("Out of memory, when modulating bits for tag answer:");
+    Dbhexdump(response_info->response_n,response_info->response,false);
+    return false;
+  }
+  
+  // Copy the byte array, used for this modulation to the buffer position
+  memcpy(response_info->modulation,ToSend,ToSendMax);
+  
+  // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
+  response_info->modulation_n = ToSendMax;
+  response_info->ProxToAirDuration = LastProxToAirDuration;
+  
+  return true;
+}
+
+bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
+  // Retrieve and store the current buffer index
+  response_info->modulation = free_buffer_pointer;
+  
+  // Determine the maximum size we can use from our buffer
+  size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
+  
+  // Forward the prepare tag modulation function to the inner function
+  if (prepare_tag_modulation(response_info,max_buffer_size)) {
+    // Update the free buffer offset
+    free_buffer_pointer += ToSendMax;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+//-----------------------------------------------------------------------------
+// Main loop of simulated tag: receive commands from reader, decide what
+// response to send, and send it.
+//-----------------------------------------------------------------------------
+void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
+{
+	// Enable and clear the trace
+	iso14a_clear_trace();
+	iso14a_set_tracing(TRUE);
+
+	uint8_t sak;
+
+	// The first response contains the ATQA (note: bytes are transmitted in reverse order).
+	uint8_t response1[2];
+	
+	switch (tagType) {
+		case 1: { // MIFARE Classic
+			// Says: I am Mifare 1k - original line
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x08;
+		} break;
+		case 2: { // MIFARE Ultralight
+			// Says: I am a stupid memory tag, no crypto
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x00;
+		} break;
+		case 3: { // MIFARE DESFire
+			// Says: I am a DESFire tag, ph33r me
+			response1[0] = 0x04;
+			response1[1] = 0x03;
+			sak = 0x20;
+		} break;
+		case 4: { // ISO/IEC 14443-4
+			// Says: I am a javacard (JCOP)
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x28;
+		} break;
+		default: {
+			Dbprintf("Error: unkown tagtype (%d)",tagType);
+			return;
+		} break;
+	}
+	
+	// The second response contains the (mandatory) first 24 bits of the UID
+	uint8_t response2[5];
+
+	// Check if the uid uses the (optional) part
+	uint8_t response2a[5];
+	if (uid_2nd) {
+		response2[0] = 0x88;
+		num_to_bytes(uid_1st,3,response2+1);
+		num_to_bytes(uid_2nd,4,response2a);
+		response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
+
+		// Configure the ATQA and SAK accordingly
+		response1[0] |= 0x40;
+		sak |= 0x04;
+	} else {
+		num_to_bytes(uid_1st,4,response2);
+		// Configure the ATQA and SAK accordingly
+		response1[0] &= 0xBF;
+		sak &= 0xFB;
+	}
+
+	// Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
+	response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
+
+	// Prepare the mandatory SAK (for 4 and 7 byte UID)
+	uint8_t response3[3];
+	response3[0] = sak;
+	ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
+
+	// Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
+	uint8_t response3a[3];
+	response3a[0] = sak & 0xFB;
+	ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
+
+	uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
+	uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
+	ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
+
+	#define TAG_RESPONSE_COUNT 7
+	tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
+		{ .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
+		{ .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
+		{ .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
+		{ .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
+		{ .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
+		{ .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
+		{ .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
+	};
+
+	// Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
+	// Such a response is less time critical, so we can prepare them on the fly
+	#define DYNAMIC_RESPONSE_BUFFER_SIZE 64
+	#define DYNAMIC_MODULATION_BUFFER_SIZE 512
+	uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
+	uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
+	tag_response_info_t dynamic_response_info = {
+		.response = dynamic_response_buffer,
+		.response_n = 0,
+		.modulation = dynamic_modulation_buffer,
+		.modulation_n = 0
+	};
+  
+	// Reset the offset pointer of the free buffer
+	reset_free_buffer();
+  
+	// Prepare the responses of the anticollision phase
+	// there will be not enough time to do this at the moment the reader sends it REQA
+	for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
+		prepare_allocated_tag_modulation(&responses[i]);
+	}
+
+	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	int len = 0;
+
+	// To control where we are in the protocol
+	int order = 0;
+	int lastorder;
+
+	// Just to allow some checks
+	int happened = 0;
+	int happened2 = 0;
+	int cmdsRecvd = 0;
+
+	// We need to listen to the high-frequency, peak-detected path.
+	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+	cmdsRecvd = 0;
+	tag_response_info_t* p_response;
+
+	LED_A_ON();
+	for(;;) {
+		// Clean receive command buffer
+		
+		if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
+			DbpString("Button press");
+			break;
+		}
+
+		p_response = NULL;
+		
+		// doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
+		// Okay, look at the command now.
+		lastorder = order;
+		if(receivedCmd[0] == 0x26) { // Received a REQUEST
+			p_response = &responses[0]; order = 1;
+		} else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
+			p_response = &responses[0]; order = 6;
+		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {	// Received request for UID (cascade 1)
+			p_response = &responses[1]; order = 2;
+		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
+			p_response = &responses[2]; order = 20;
+		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {	// Received a SELECT (cascade 1)
+			p_response = &responses[3]; order = 3;
+		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {	// Received a SELECT (cascade 2)
+			p_response = &responses[4]; order = 30;
+		} else if(receivedCmd[0] == 0x30) {	// Received a (plain) READ
+			EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
+			// Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
+			// We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
+			p_response = NULL;
+		} else if(receivedCmd[0] == 0x50) {	// Received a HALT
+//			DbpString("Reader requested we HALT!:");
+			if (tracing) {
+				LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+			}
+			p_response = NULL;
+		} else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {	// Received an authentication request
+			p_response = &responses[5]; order = 7;
+		} else if(receivedCmd[0] == 0xE0) {	// Received a RATS request
+			if (tagType == 1 || tagType == 2) {	// RATS not supported
+				EmSend4bit(CARD_NACK_NA);
+				p_response = NULL;
+			} else {
+				p_response = &responses[6]; order = 70;
+			}
+		} else if (order == 7 && len == 8) { // Received authentication request
+			if (tracing) {
+				LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+			}
+			uint32_t nr = bytes_to_num(receivedCmd,4);
+			uint32_t ar = bytes_to_num(receivedCmd+4,4);
+			Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
+		} else {
+			// Check for ISO 14443A-4 compliant commands, look at left nibble
+			switch (receivedCmd[0]) {
+
+				case 0x0B:
+				case 0x0A: { // IBlock (command)
+				  dynamic_response_info.response[0] = receivedCmd[0];
+				  dynamic_response_info.response[1] = 0x00;
+				  dynamic_response_info.response[2] = 0x90;
+				  dynamic_response_info.response[3] = 0x00;
+				  dynamic_response_info.response_n = 4;
+				} break;
+
+				case 0x1A:
+				case 0x1B: { // Chaining command
+				  dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
+				  dynamic_response_info.response_n = 2;
+				} break;
+
+				case 0xaa:
+				case 0xbb: {
+				  dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
+				  dynamic_response_info.response_n = 2;
+				} break;
+				  
+				case 0xBA: { //
+				  memcpy(dynamic_response_info.response,"\xAB\x00",2);
+				  dynamic_response_info.response_n = 2;
+				} break;
+
+				case 0xCA:
+				case 0xC2: { // Readers sends deselect command
+				  memcpy(dynamic_response_info.response,"\xCA\x00",2);
+				  dynamic_response_info.response_n = 2;
+				} break;
+
+				default: {
+					// Never seen this command before
+					if (tracing) {
+						LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+						LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					}
+					Dbprintf("Received unknown command (len=%d):",len);
+					Dbhexdump(len,receivedCmd,false);
+					// Do not respond
+					dynamic_response_info.response_n = 0;
+				} break;
+			}
+      
+			if (dynamic_response_info.response_n > 0) {
+				// Copy the CID from the reader query
+				dynamic_response_info.response[1] = receivedCmd[1];
+
+				// Add CRC bytes, always used in ISO 14443A-4 compliant cards
+				AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
+				dynamic_response_info.response_n += 2;
+        
+				if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
+					Dbprintf("Error preparing tag response");
+					if (tracing) {
+						LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+						LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					}
+					break;
+				}
+				p_response = &dynamic_response_info;
+			}
+		}
+
+		// Count number of wakeups received after a halt
+		if(order == 6 && lastorder == 5) { happened++; }
+
+		// Count number of other messages after a halt
+		if(order != 6 && lastorder == 5) { happened2++; }
+
+		if(cmdsRecvd > 999) {
+			DbpString("1000 commands later...");
+			break;
+		}
+		cmdsRecvd++;
+
+		if (p_response != NULL) {
+			EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
+			// do the tracing for the previous reader request and this tag answer:
+			EmLogTrace(Uart.output, 
+						Uart.len, 
+						Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+						Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+						Uart.parityBits,
+						p_response->response, 
+						p_response->response_n,
+						LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+						(LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+						SwapBits(GetParity(p_response->response, p_response->response_n), p_response->response_n));
+		}
+		
+		if (!tracing) {
+			Dbprintf("Trace Full. Simulation stopped.");
+			break;
+		}
+	}
+
+	Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
+	LED_A_OFF();
+}
+
+
+// prepare a delayed transfer. This simply shifts ToSend[] by a number
+// of bits specified in the delay parameter.
+void PrepareDelayedTransfer(uint16_t delay)
+{
+	uint8_t bitmask = 0;
+	uint8_t bits_to_shift = 0;
+	uint8_t bits_shifted = 0;
+	
+	delay &= 0x07;
+	if (delay) {
+		for (uint16_t i = 0; i < delay; i++) {
+			bitmask |= (0x01 << i);
+		}
+		ToSend[ToSendMax++] = 0x00;
+		for (uint16_t i = 0; i < ToSendMax; i++) {
+			bits_to_shift = ToSend[i] & bitmask;
+			ToSend[i] = ToSend[i] >> delay;
+			ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
+			bits_shifted = bits_to_shift;
+		}
+	}
+}
+
+
+//-------------------------------------------------------------------------------------
+// Transmit the command (to the tag) that was placed in ToSend[].
+// Parameter timing:
+// if NULL: transfer at next possible time, taking into account
+// 			request guard time and frame delay time
+// if == 0:	transfer immediately and return time of transfer
+// if != 0: delay transfer until time specified
+//-------------------------------------------------------------------------------------
+static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
+{
+	
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+
+	uint32_t ThisTransferTime = 0;
+
+	if (timing) {
+		if(*timing == 0) {										// Measure time
+			*timing = (GetCountSspClk() + 8) & 0xfffffff8;
+		} else {
+			PrepareDelayedTransfer(*timing & 0x00000007);		// Delay transfer (fine tuning - up to 7 MF clock ticks)
+		}
+		if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+		while(GetCountSspClk() < (*timing & 0xfffffff8));		// Delay transfer (multiple of 8 MF clock ticks)
+		LastTimeProxToAirStart = *timing;
+	} else {
+		ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
+		while(GetCountSspClk() < ThisTransferTime);
+		LastTimeProxToAirStart = ThisTransferTime;
+	}
+	
+	// clear TXRDY
+	AT91C_BASE_SSC->SSC_THR = SEC_Y;
+
+	// for(uint16_t c = 0; c < 10;) {	// standard delay for each transfer (allow tag to be ready after last transmission)
+		// if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			// AT91C_BASE_SSC->SSC_THR = SEC_Y;	
+			// c++;
+		// }
+	// }
+
+	uint16_t c = 0;
+	for(;;) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			AT91C_BASE_SSC->SSC_THR = cmd[c];
+			c++;
+			if(c >= len) {
+				break;
+			}
+		}
+	}
+	
+	NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
+	
+}
+
+
+//-----------------------------------------------------------------------------
+// Prepare reader command (in bits, support short frames) to send to FPGA
+//-----------------------------------------------------------------------------
+void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
+{
+	int i, j;
+	int last;
+	uint8_t b;
+
+	ToSendReset();
+
+	// Start of Communication (Seq. Z)
+	ToSend[++ToSendMax] = SEC_Z;
+	LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+	last = 0;
+
+	size_t bytecount = nbytes(bits);
+	// Generate send structure for the data bits
+	for (i = 0; i < bytecount; i++) {
+		// Get the current byte to send
+		b = cmd[i];
+		size_t bitsleft = MIN((bits-(i*8)),8);
+
+		for (j = 0; j < bitsleft; j++) {
+			if (b & 1) {
+				// Sequence X
+				ToSend[++ToSendMax] = SEC_X;
+				LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+				last = 1;
+			} else {
+				if (last == 0) {
+				// Sequence Z
+				ToSend[++ToSendMax] = SEC_Z;
+				LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+				} else {
+					// Sequence Y
+					ToSend[++ToSendMax] = SEC_Y;
+					last = 0;
+				}
+			}
+			b >>= 1;
+		}
+
+		// Only transmit (last) parity bit if we transmitted a complete byte
+		if (j == 8) {
+			// Get the parity bit
+			if ((dwParity >> i) & 0x01) {
+				// Sequence X
+				ToSend[++ToSendMax] = SEC_X;
+				LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+				last = 1;
+			} else {
+				if (last == 0) {
+					// Sequence Z
+					ToSend[++ToSendMax] = SEC_Z;
+					LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+				} else {
+					// Sequence Y
+					ToSend[++ToSendMax] = SEC_Y;
+					last = 0;
+				}
+			}
+		}
+	}
+
+	// End of Communication: Logic 0 followed by Sequence Y
+	if (last == 0) {
+		// Sequence Z
+		ToSend[++ToSendMax] = SEC_Z;
+		LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+	} else {
+		// Sequence Y
+		ToSend[++ToSendMax] = SEC_Y;
+		last = 0;
+	}
+	ToSend[++ToSendMax] = SEC_Y;
+
+	// Convert to length of command:
+	ToSendMax++;
+}
+
+//-----------------------------------------------------------------------------
+// Prepare reader command to send to FPGA
+//-----------------------------------------------------------------------------
+void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
+{
+  CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
+}
+
+//-----------------------------------------------------------------------------
+// Wait for commands from reader
+// Stop when button is pressed (return 1) or field was gone (return 2)
+// Or return 0 when command is captured
+//-----------------------------------------------------------------------------
+static int EmGetCmd(uint8_t *received, int *len)
+{
+	*len = 0;
+
+	uint32_t timer = 0, vtime = 0;
+	int analogCnt = 0;
+	int analogAVG = 0;
+
+	// Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
+	// only, since we are receiving, not transmitting).
+	// Signal field is off with the appropriate LED
+	LED_D_OFF();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+	// Set ADC to read field strength
+	AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
+	AT91C_BASE_ADC->ADC_MR =
+				ADC_MODE_PRESCALE(32) |
+				ADC_MODE_STARTUP_TIME(16) |
+				ADC_MODE_SAMPLE_HOLD_TIME(8);
+	AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
+	// start ADC
+	AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+	
+	// Now run a 'software UART' on the stream of incoming samples.
+	UartReset();
+	Uart.output = received;
+
+	// Clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+
+	for(;;) {
+		WDT_HIT();
+
+		if (BUTTON_PRESS()) return 1;
+
+		// test if the field exists
+		if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
+			analogCnt++;
+			analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
+			AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+			if (analogCnt >= 32) {
+				if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
+					vtime = GetTickCount();
+					if (!timer) timer = vtime;
+					// 50ms no field --> card to idle state
+					if (vtime - timer > 50) return 2;
+				} else
+					if (timer) timer = 0;
+				analogCnt = 0;
+				analogAVG = 0;
+			}
+		}
+
+		// receive and test the miller decoding
+        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+            b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			if(MillerDecoding(b, 0)) {
+				*len = Uart.len;
+				return 0;
+			}
+        }
+
+	}
+}
+
+
+static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded)
+{
+	uint8_t b;
+	uint16_t i = 0;
+	uint32_t ThisTransferTime;
+	
+	// Modulate Manchester
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
+
+	// include correction bit if necessary
+	if (Uart.parityBits & 0x01) {
+		correctionNeeded = TRUE;
+	}
+	if(correctionNeeded) {
+		// 1236, so correction bit needed
+		i = 0;
+	} else {
+		i = 1;
+	}
+
+ 	// clear receiving shift register and holding register
+	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+	b = AT91C_BASE_SSC->SSC_RHR; (void) b;
+	while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+	b = AT91C_BASE_SSC->SSC_RHR; (void) b;
+	
+	// wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
+	for (uint16_t j = 0; j < 5; j++) {	// allow timeout - better late than never
+		while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+		if (AT91C_BASE_SSC->SSC_RHR) break;
+	}
+
+	while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
+
+	// Clear TXRDY:
+	AT91C_BASE_SSC->SSC_THR = SEC_F;
+
+	// send cycle
+	for(; i <= respLen; ) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			AT91C_BASE_SSC->SSC_THR = resp[i++];
+			FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+		}
+	
+		if(BUTTON_PRESS()) {
+			break;
+		}
+	}
+
+	// Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
+	for (i = 0; i < 2 ; ) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			AT91C_BASE_SSC->SSC_THR = SEC_F;
+			FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			i++;
+		}
+	}
+	
+	LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
+
+	return 0;
+}
+
+int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
+	Code4bitAnswerAsTag(resp);
+	int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
+	// do the tracing for the previous reader request and this tag answer:
+	EmLogTrace(Uart.output, 
+				Uart.len, 
+				Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+				Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+				Uart.parityBits,
+				&resp, 
+				1, 
+				LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+				(LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+				SwapBits(GetParity(&resp, 1), 1));
+	return res;
+}
+
+int EmSend4bit(uint8_t resp){
+	return EmSend4bitEx(resp, false);
+}
+
+int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par){
+	CodeIso14443aAsTagPar(resp, respLen, par);
+	int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
+	// do the tracing for the previous reader request and this tag answer:
+	EmLogTrace(Uart.output, 
+				Uart.len, 
+				Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, 
+				Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 
+				Uart.parityBits,
+				resp, 
+				respLen, 
+				LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
+				(LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, 
+				SwapBits(GetParity(resp, respLen), respLen));
+	return res;
+}
+
+int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded){
+	return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
+}
+
+int EmSendCmd(uint8_t *resp, int respLen){
+	return EmSendCmdExPar(resp, respLen, false, GetParity(resp, respLen));
+}
+
+int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
+	return EmSendCmdExPar(resp, respLen, false, par);
+}
+
+bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
+				 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity)
+{
+	if (tracing) {
+		// we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
+		// end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
+		// with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
+		uint16_t reader_modlen = reader_EndTime - reader_StartTime;
+		uint16_t approx_fdt = tag_StartTime - reader_EndTime;
+		uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
+		reader_EndTime = tag_StartTime - exact_fdt;
+		reader_StartTime = reader_EndTime - reader_modlen;
+		if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_Parity, TRUE)) {
+			return FALSE;
+		} else if (!LogTrace(NULL, 0, reader_EndTime, 0, TRUE)) {
+			return FALSE;
+		} else if (!LogTrace(tag_data, tag_len, tag_StartTime, tag_Parity, FALSE)) {
+			return FALSE;
+		} else {
+			return (!LogTrace(NULL, 0, tag_EndTime, 0, FALSE));
+		}
+	} else {
+		return TRUE;
+	}
+}
+
+//-----------------------------------------------------------------------------
+// Wait a certain time for tag response
+//  If a response is captured return TRUE
+//  If it takes too long return FALSE
+//-----------------------------------------------------------------------------
+static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen)
+{
+	uint16_t c;
+	
+	// Set FPGA mode to "reader listen mode", no modulation (listen
+	// only, since we are receiving, not transmitting).
+	// Signal field is on with the appropriate LED
+	LED_D_ON();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
+	
+	// Now get the answer from the card
+	DemodReset();
+	Demod.output = receivedResponse;
+
+	// clear RXRDY:
+    uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+	
+	c = 0;
+	for(;;) {
+		WDT_HIT();
+
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+			b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			if(ManchesterDecoding(b, offset, 0)) {
+				NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
+				return TRUE;
+			} else if(c++ > iso14a_timeout) {
+				return FALSE; 
+			}
+		}
+	}
+}
+
+void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
+{
+
+	CodeIso14443aBitsAsReaderPar(frame,bits,par);
+  
+	// Send command to tag
+	TransmitFor14443a(ToSend, ToSendMax, timing);
+	if(trigger)
+		LED_A_ON();
+  
+	// Log reader command in trace buffer
+	if (tracing) {
+		LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
+		LogTrace(NULL, 0, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, 0, TRUE);
+	}
+}
+
+void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
+{
+  ReaderTransmitBitsPar(frame,len*8,par, timing);
+}
+
+void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
+{
+  // Generate parity and redirect
+  ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
+}
+
+void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
+{
+  // Generate parity and redirect
+  ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
+}
+
+int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
+{
+	if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160)) return FALSE;
+	if (tracing) {
+		LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
+		LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
+	}
+	return Demod.len;
+}
+
+int ReaderReceive(uint8_t* receivedAnswer)
+{
+	return ReaderReceiveOffset(receivedAnswer, 0);
+}
+
+int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
+{
+	if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160)) return FALSE;
+	if (tracing) {
+		LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
+		LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
+	}
+	*parptr = Demod.parityBits;
+	return Demod.len;
+}
+
+/* performs iso14443a anticollision procedure
+ * fills the uid pointer unless NULL
+ * fills resp_data unless NULL */
+int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
+  uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
+  uint8_t sel_all[]    = { 0x93,0x20 };
+  uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+  uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
+  uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);	// was 3560 - tied to other size changes
+  byte_t uid_resp[4];
+  size_t uid_resp_len;
+
+  uint8_t sak = 0x04; // cascade uid
+  int cascade_level = 0;
+  int len;
+	 
+  // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+    ReaderTransmitBitsPar(wupa,7,0, NULL);
+	
+  // Receive the ATQA
+  if(!ReaderReceive(resp)) return 0;
+  // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
+
+  if(p_hi14a_card) {
+    memcpy(p_hi14a_card->atqa, resp, 2);
+    p_hi14a_card->uidlen = 0;
+    memset(p_hi14a_card->uid,0,10);
+  }
+
+  // clear uid
+  if (uid_ptr) {
+    memset(uid_ptr,0,10);
+  }
+
+  // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
+  // which case we need to make a cascade 2 request and select - this is a long UID
+  // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
+  for(; sak & 0x04; cascade_level++) {
+    // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
+    sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
+
+    // SELECT_ALL
+    ReaderTransmit(sel_all,sizeof(sel_all), NULL);
+    if (!ReaderReceive(resp)) return 0;
+
+	if (Demod.collisionPos) {			// we had a collision and need to construct the UID bit by bit
+		memset(uid_resp, 0, 4);
+		uint16_t uid_resp_bits = 0;
+		uint16_t collision_answer_offset = 0;
+		// anti-collision-loop:
+		while (Demod.collisionPos) {
+			Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
+			for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {	// add valid UID bits before collision point
+				uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
+				uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
+			}
+			uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);					// next time select the card(s) with a 1 in the collision position
+			uid_resp_bits++;
+			// construct anticollosion command:
+			sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);  	// length of data in bytes and bits
+			for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
+				sel_uid[2+i] = uid_resp[i];
+			}
+			collision_answer_offset = uid_resp_bits%8;
+			ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
+			if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
+		}
+		// finally, add the last bits and BCC of the UID
+		for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
+			uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
+			uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
+		}
+
+	} else {		// no collision, use the response to SELECT_ALL as current uid
+		memcpy(uid_resp,resp,4);
+	}
+	uid_resp_len = 4;
+       // Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
+
+    // calculate crypto UID. Always use last 4 Bytes.
+    if(cuid_ptr) {
+        *cuid_ptr = bytes_to_num(uid_resp, 4);
+    }
+
+    // Construct SELECT UID command
+	sel_uid[1] = 0x70;													// transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
+    memcpy(sel_uid+2,uid_resp,4);										// the UID
+	sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];  	// calculate and add BCC
+    AppendCrc14443a(sel_uid,7);											// calculate and add CRC
+    ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
+
+    // Receive the SAK
+    if (!ReaderReceive(resp)) return 0;
+    sak = resp[0];
+
+    // Test if more parts of the uid are comming
+    if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
+      // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
+      // http://www.nxp.com/documents/application_note/AN10927.pdf
+      memcpy(uid_resp, uid_resp + 1, 3);
+      uid_resp_len = 3;
+    }
+
+    if(uid_ptr) {
+      memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
+    }
+
+    if(p_hi14a_card) {
+      memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
+      p_hi14a_card->uidlen += uid_resp_len;
+    }
+  }
+
+  if(p_hi14a_card) {
+    p_hi14a_card->sak = sak;
+    p_hi14a_card->ats_len = 0;
+  }
+
+  if( (sak & 0x20) == 0) {
+    return 2; // non iso14443a compliant tag
+  }
+
+  // Request for answer to select
+  AppendCrc14443a(rats, 2);
+  ReaderTransmit(rats, sizeof(rats), NULL);
+
+  if (!(len = ReaderReceive(resp))) return 0;
+
+  if(p_hi14a_card) {
+    memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
+    p_hi14a_card->ats_len = len;
+  }
+
+  // reset the PCB block number
+  iso14_pcb_blocknum = 0;
+  return 1;
+}
+
+void iso14443a_setup(uint8_t fpga_minor_mode) {
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+	// Set up the synchronous serial port
+	FpgaSetupSsc();
+	// connect Demodulated Signal to ADC:
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+	// Signal field is on with the appropriate LED
+	if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
+		|| fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
+		LED_D_ON();
+	} else {
+		LED_D_OFF();
+	}
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
+
+	// Start the timer
+	StartCountSspClk();
+	
+	DemodReset();
+	UartReset();
+	NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
+	iso14a_set_timeout(1050); // 10ms default
+}
+
+int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
+	uint8_t real_cmd[cmd_len+4];
+	real_cmd[0] = 0x0a; //I-Block
+	// put block number into the PCB
+	real_cmd[0] |= iso14_pcb_blocknum;
+	real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
+	memcpy(real_cmd+2, cmd, cmd_len);
+	AppendCrc14443a(real_cmd,cmd_len+2);
+ 
+	ReaderTransmit(real_cmd, cmd_len+4, NULL);
+	size_t len = ReaderReceive(data);
+	uint8_t * data_bytes = (uint8_t *) data;
+	if (!len)
+		return 0; //DATA LINK ERROR
+	// if we received an I- or R(ACK)-Block with a block number equal to the
+	// current block number, toggle the current block number
+	else if (len >= 4 // PCB+CID+CRC = 4 bytes
+	         && ((data_bytes[0] & 0xC0) == 0 // I-Block
+	             || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
+	         && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
+	{
+		iso14_pcb_blocknum ^= 1;
+	}
+
+	return len;
+}
+
+//-----------------------------------------------------------------------------
+// Read an ISO 14443a tag. Send out commands and store answers.
+//
+//-----------------------------------------------------------------------------
+void ReaderIso14443a(UsbCommand *c)
+{
+	iso14a_command_t param = c->arg[0];
+	uint8_t *cmd = c->d.asBytes;
+	size_t len = c->arg[1];
+	size_t lenbits = c->arg[2];
+	uint32_t arg0 = 0;
+	byte_t buf[USB_CMD_DATA_SIZE];
+  
+	if(param & ISO14A_CONNECT) {
+		iso14a_clear_trace();
+	}
+
+	iso14a_set_tracing(TRUE);
+
+	if(param & ISO14A_REQUEST_TRIGGER) {
+		iso14a_set_trigger(TRUE);
+	}
+
+	if(param & ISO14A_CONNECT) {
+		iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
+		if(!(param & ISO14A_NO_SELECT)) {
+			iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
+			arg0 = iso14443a_select_card(NULL,card,NULL);
+			cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
+		}
+	}
+
+	if(param & ISO14A_SET_TIMEOUT) {
+		iso14a_timeout = c->arg[2];
+	}
+
+	if(param & ISO14A_APDU) {
+		arg0 = iso14_apdu(cmd, len, buf);
+		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
+	}
+
+	if(param & ISO14A_RAW) {
+		if(param & ISO14A_APPEND_CRC) {
+			AppendCrc14443a(cmd,len);
+			len += 2;
+			lenbits += 16;
+		}
+		if(lenbits>0) {
+
+			ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
+		} else {
+			ReaderTransmit(cmd,len, NULL);
+		}
+		arg0 = ReaderReceive(buf);
+		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
+	}
+
+	if(param & ISO14A_REQUEST_TRIGGER) {
+		iso14a_set_trigger(FALSE);
+	}
+
+	if(param & ISO14A_NO_DISCONNECT) {
+		return;
+	}
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LEDsoff();
+}
+
+
+// Determine the distance between two nonces.
+// Assume that the difference is small, but we don't know which is first.
+// Therefore try in alternating directions.
+int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
+
+	uint16_t i;
+	uint32_t nttmp1, nttmp2;
+
+	if (nt1 == nt2) return 0;
+
+	nttmp1 = nt1;
+	nttmp2 = nt2;
+	
+	for (i = 1; i < 32768; i++) {
+		nttmp1 = prng_successor(nttmp1, 1);
+		if (nttmp1 == nt2) return i;
+		nttmp2 = prng_successor(nttmp2, 1);
+			if (nttmp2 == nt1) return -i;
+		}
+	
+	return(-99999); // either nt1 or nt2 are invalid nonces
+}
+
+
+//-----------------------------------------------------------------------------
+// Recover several bits of the cypher stream. This implements (first stages of)
+// the algorithm described in "The Dark Side of Security by Obscurity and
+// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
+// (article by Nicolas T. Courtois, 2009)
+//-----------------------------------------------------------------------------
+void ReaderMifare(bool first_try)
+{
+	// Mifare AUTH
+	uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
+	uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+	static uint8_t mf_nr_ar3;
+
+	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+
+	iso14a_clear_trace();
+	iso14a_set_tracing(TRUE);
+
+	byte_t nt_diff = 0;
+	byte_t par = 0;
+	//byte_t par_mask = 0xff;
+	static byte_t par_low = 0;
+	bool led_on = TRUE;
+	uint8_t uid[10];
+	uint32_t cuid;
+
+	uint32_t nt, previous_nt;
+	static uint32_t nt_attacked = 0;
+	byte_t par_list[8] = {0,0,0,0,0,0,0,0};
+	byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
+
+	static uint32_t sync_time;
+	static uint32_t sync_cycles;
+	int catch_up_cycles = 0;
+	int last_catch_up = 0;
+	uint16_t consecutive_resyncs = 0;
+	int isOK = 0;
+
+
+
+	if (first_try) { 
+		mf_nr_ar3 = 0;
+		iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+		sync_time = GetCountSspClk() & 0xfffffff8;
+		sync_cycles = 65536;									// theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+		nt_attacked = 0;
+		nt = 0;
+		par = 0;
+	}
+	else {
+		// we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
+		// nt_attacked = prng_successor(nt_attacked, 1);
+		mf_nr_ar3++;
+		mf_nr_ar[3] = mf_nr_ar3;
+		par = par_low;
+	}
+
+	LED_A_ON();
+	LED_B_OFF();
+	LED_C_OFF();
+	
+  
+	for(uint16_t i = 0; TRUE; i++) {
+		
+		WDT_HIT();
+
+		// Test if the action was cancelled
+		if(BUTTON_PRESS()) {
+			break;
+		}
+		
+		LED_C_ON();
+
+		if(!iso14443a_select_card(uid, NULL, &cuid)) {
+			if (MF_DBGLEVEL >= 1)	Dbprintf("Mifare: Can't select card");
+			continue;
+		}
+
+		sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+		catch_up_cycles = 0;
+
+		// if we missed the sync time already, advance to the next nonce repeat
+		while(GetCountSspClk() > sync_time) {
+			sync_time = (sync_time & 0xfffffff8) + sync_cycles;
+		}
+
+		// Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) 
+		ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+
+		// Receive the (4 Byte) "random" nonce
+		if (!ReaderReceive(receivedAnswer)) {
+			if (MF_DBGLEVEL >= 1)	Dbprintf("Mifare: Couldn't receive tag nonce");
+			continue;
+		  }
+
+		previous_nt = nt;
+		nt = bytes_to_num(receivedAnswer, 4);
+
+		// Transmit reader nonce with fake par
+		ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
+
+		if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
+			int nt_distance = dist_nt(previous_nt, nt);
+			if (nt_distance == 0) {
+				nt_attacked = nt;
+			}
+			else {
+				if (nt_distance == -99999) { // invalid nonce received, try again
+					continue;
+				}
+				sync_cycles = (sync_cycles - nt_distance);
+				if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
+				continue;
+			}
+		}
+
+		if ((nt != nt_attacked) && nt_attacked) { 	// we somehow lost sync. Try to catch up again...
+			catch_up_cycles = -dist_nt(nt_attacked, nt);
+			if (catch_up_cycles == 99999) {			// invalid nonce received. Don't resync on that one.
+				catch_up_cycles = 0;
+				continue;
+			}
+			if (catch_up_cycles == last_catch_up) {
+				consecutive_resyncs++;
+			}
+			else {
+				last_catch_up = catch_up_cycles;
+			    consecutive_resyncs = 0;
+			}
+			if (consecutive_resyncs < 3) {
+				if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
+			}
+			else {	
+				sync_cycles = sync_cycles + catch_up_cycles;
+				if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
+			}
+			continue;
+		}
+ 
+		consecutive_resyncs = 0;
+		
+		// Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
+		if (ReaderReceive(receivedAnswer))
+		{
+			catch_up_cycles = 8; 	// the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
+	
+			if (nt_diff == 0)
+			{
+				par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
+			}
+
+			led_on = !led_on;
+			if(led_on) LED_B_ON(); else LED_B_OFF();
+
+			par_list[nt_diff] = par;
+			ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
+
+			// Test if the information is complete
+			if (nt_diff == 0x07) {
+				isOK = 1;
+				break;
+			}
+
+			nt_diff = (nt_diff + 1) & 0x07;
+			mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
+			par = par_low;
+		} else {
+			if (nt_diff == 0 && first_try)
+			{
+				par++;
+			} else {
+				par = (((par >> 3) + 1) << 3) | par_low;
+			}
+		}
+	}
+
+
+	mf_nr_ar[3] &= 0x1F;
+	
+	byte_t buf[28];
+	memcpy(buf + 0,  uid, 4);
+	num_to_bytes(nt, 4, buf + 4);
+	memcpy(buf + 8,  par_list, 8);
+	memcpy(buf + 16, ks_list, 8);
+	memcpy(buf + 24, mf_nr_ar, 4);
+		
+	cmd_send(CMD_ACK,isOK,0,0,buf,28);
+
+	// Thats it...
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LEDsoff();
+
+	iso14a_set_tracing(FALSE);
+}
+
+/**
+  *MIFARE 1K simulate.
+  *
+  *@param flags :
+  *	FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
+  * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
+  * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
+  *	FLAG_NR_AR_ATTACK  - means we should collect NR_AR responses for bruteforcing later
+  *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
+  */
+void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
+{
+	int cardSTATE = MFEMUL_NOFIELD;
+	int _7BUID = 0;
+	int vHf = 0;	// in mV
+	int res;
+	uint32_t selTimer = 0;
+	uint32_t authTimer = 0;
+	uint32_t par = 0;
+	int len = 0;
+	uint8_t cardWRBL = 0;
+	uint8_t cardAUTHSC = 0;
+	uint8_t cardAUTHKEY = 0xff;  // no authentication
+	uint32_t cardRr = 0;
+	uint32_t cuid = 0;
+	//uint32_t rn_enc = 0;
+	uint32_t ans = 0;
+	uint32_t cardINTREG = 0;
+	uint8_t cardINTBLOCK = 0;
+	struct Crypto1State mpcs = {0, 0};
+	struct Crypto1State *pcs;
+	pcs = &mpcs;
+	uint32_t numReads = 0;//Counts numer of times reader read a block
+	uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
+	uint8_t *response = eml_get_bigbufptr_sendbuf();
+	
+	uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
+	uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
+	uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
+	uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
+	uint8_t rSAK1[] = {0x04, 0xda, 0x17};
+
+	uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
+	uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
+		
+	//Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
+	// This can be used in a reader-only attack.
+	// (it can also be retrieved via 'hf 14a list', but hey...
+	uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
+	uint8_t ar_nr_collected = 0;
+
+	// clear trace
+    iso14a_clear_trace();
+	iso14a_set_tracing(TRUE);
+
+	// Authenticate response - nonce
+	uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
+	
+	//-- Determine the UID
+	// Can be set from emulator memory, incoming data
+	// and can be 7 or 4 bytes long
+	if (flags & FLAG_4B_UID_IN_DATA)
+	{
+		// 4B uid comes from data-portion of packet
+		memcpy(rUIDBCC1,datain,4);
+		rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
+
+	} else if (flags & FLAG_7B_UID_IN_DATA) {
+		// 7B uid comes from data-portion of packet
+		memcpy(&rUIDBCC1[1],datain,3);
+		memcpy(rUIDBCC2, datain+3, 4);
+		_7BUID = true;
+	} else {
+		// get UID from emul memory
+		emlGetMemBt(receivedCmd, 7, 1);
+		_7BUID = !(receivedCmd[0] == 0x00);
+		if (!_7BUID) {                     // ---------- 4BUID
+			emlGetMemBt(rUIDBCC1, 0, 4);
+		} else {                           // ---------- 7BUID
+			emlGetMemBt(&rUIDBCC1[1], 0, 3);
+			emlGetMemBt(rUIDBCC2, 3, 4);
+		}
+	}
+
+	/*
+	 * Regardless of what method was used to set the UID, set fifth byte and modify
+	 * the ATQA for 4 or 7-byte UID
+	 */
+	rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
+	if (_7BUID) {
+		rATQA[0] = 0x44;
+		rUIDBCC1[0] = 0x88;
+		rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
+	}
+
+	// We need to listen to the high-frequency, peak-detected path.
+	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+
+	if (MF_DBGLEVEL >= 1)	{
+		if (!_7BUID) {
+			Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
+		} else {
+			Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
+		}
+	}
+
+	bool finished = FALSE;
+	while (!BUTTON_PRESS() && !finished) {
+		WDT_HIT();
+
+		// find reader field
+		// Vref = 3300mV, and an 10:1 voltage divider on the input
+		// can measure voltages up to 33000 mV
+		if (cardSTATE == MFEMUL_NOFIELD) {
+			vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
+			if (vHf > MF_MINFIELDV) {
+				cardSTATE_TO_IDLE();
+				LED_A_ON();
+			}
+		} 
+		if(cardSTATE == MFEMUL_NOFIELD) continue;
+
+		//Now, get data
+
+		res = EmGetCmd(receivedCmd, &len);
+		if (res == 2) { //Field is off!
+			cardSTATE = MFEMUL_NOFIELD;
+			LEDsoff();
+			continue;
+		} else if (res == 1) {
+			break; 	//return value 1 means button press
+		}
+			
+		// REQ or WUP request in ANY state and WUP in HALTED state
+		if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
+			selTimer = GetTickCount();
+			EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
+			cardSTATE = MFEMUL_SELECT1;
+
+			// init crypto block
+			LED_B_OFF();
+			LED_C_OFF();
+			crypto1_destroy(pcs);
+			cardAUTHKEY = 0xff;
+			continue;
+		}
+		
+		switch (cardSTATE) {
+			case MFEMUL_NOFIELD:
+			case MFEMUL_HALTED:
+			case MFEMUL_IDLE:{
+				LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+				break;
+			}
+			case MFEMUL_SELECT1:{
+				// select all
+				if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
+					if (MF_DBGLEVEL >= 4)	Dbprintf("SELECT ALL received");
+					EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
+					break;
+				}
+
+				if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
+				{
+					Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
+				}
+				// select card
+				if (len == 9 && 
+						(receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
+					EmSendCmd(_7BUID?rSAK1:rSAK, sizeof(_7BUID?rSAK1:rSAK));
+					cuid = bytes_to_num(rUIDBCC1, 4);
+					if (!_7BUID) {
+						cardSTATE = MFEMUL_WORK;
+						LED_B_ON();
+						if (MF_DBGLEVEL >= 4)	Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
+						break;
+					} else {
+						cardSTATE = MFEMUL_SELECT2;
+					}
+				}
+				break;
+			}
+			case MFEMUL_AUTH1:{
+				if( len != 8)
+				{
+					cardSTATE_TO_IDLE();
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+				uint32_t ar = bytes_to_num(receivedCmd, 4);
+				uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
+
+				//Collect AR/NR
+				if(ar_nr_collected < 2){
+					if(ar_nr_responses[2] != ar)
+					{// Avoid duplicates... probably not necessary, ar should vary. 
+						ar_nr_responses[ar_nr_collected*4] = cuid;
+						ar_nr_responses[ar_nr_collected*4+1] = nonce;
+						ar_nr_responses[ar_nr_collected*4+2] = ar;
+						ar_nr_responses[ar_nr_collected*4+3] = nr;
+						ar_nr_collected++;
+					}
+				}
+
+				// --- crypto
+				crypto1_word(pcs, ar , 1);
+				cardRr = nr ^ crypto1_word(pcs, 0, 0);
+
+				// test if auth OK
+				if (cardRr != prng_successor(nonce, 64)){
+					if (MF_DBGLEVEL >= 2)	Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
+					// Shouldn't we respond anything here?
+					// Right now, we don't nack or anything, which causes the
+					// reader to do a WUPA after a while. /Martin
+					cardSTATE_TO_IDLE();
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+
+				ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
+
+				num_to_bytes(ans, 4, rAUTH_AT);
+				// --- crypto
+				EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
+				LED_C_ON();
+				cardSTATE = MFEMUL_WORK;
+				if (MF_DBGLEVEL >= 4)	Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
+				break;
+			}
+			case MFEMUL_SELECT2:{
+				if (!len) { 
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+				if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
+					EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
+					break;
+				}
+
+				// select 2 card
+				if (len == 9 && 
+						(receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
+					EmSendCmd(rSAK, sizeof(rSAK));
+					cuid = bytes_to_num(rUIDBCC2, 4);
+					cardSTATE = MFEMUL_WORK;
+					LED_B_ON();
+					if (MF_DBGLEVEL >= 4)	Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
+					break;
+				}
+				
+				// i guess there is a command). go into the work state.
+				if (len != 4) {
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+				cardSTATE = MFEMUL_WORK;
+				//goto lbWORK;
+				//intentional fall-through to the next case-stmt
+			}
+
+			case MFEMUL_WORK:{
+				if (len == 0) {
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+				
+				bool encrypted_data = (cardAUTHKEY != 0xFF) ;
+
+				if(encrypted_data) {
+					// decrypt seqence
+					mf_crypto1_decrypt(pcs, receivedCmd, len);
+				}
+				
+				if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
+					authTimer = GetTickCount();
+					cardAUTHSC = receivedCmd[1] / 4;  // received block num
+					cardAUTHKEY = receivedCmd[0] - 0x60;
+					crypto1_destroy(pcs);//Added by martin
+					crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
+
+					if (!encrypted_data) { // first authentication
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
+
+						crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
+						num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
+					} else { // nested authentication
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
+						ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
+						num_to_bytes(ans, 4, rAUTH_AT);
+					}
+					EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
+					//Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
+					cardSTATE = MFEMUL_AUTH1;
+					break;
+				}
+				
+				// rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
+				// BUT... ACK --> NACK
+				if (len == 1 && receivedCmd[0] == CARD_ACK) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					break;
+				}
+				
+				// rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
+				if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					break;
+				}
+				
+				if(len != 4) {
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+
+				if(receivedCmd[0] == 0x30 // read block
+						|| receivedCmd[0] == 0xA0 // write block
+						|| receivedCmd[0] == 0xC0
+						|| receivedCmd[0] == 0xC1
+						|| receivedCmd[0] == 0xC2 // inc dec restore
+						|| receivedCmd[0] == 0xB0) { // transfer
+					if (receivedCmd[1] >= 16 * 4) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+						break;
+					}
+
+					if (receivedCmd[1] / 4 != cardAUTHSC) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
+						break;
+					}
+				}
+				// read block
+				if (receivedCmd[0] == 0x30) {
+					if (MF_DBGLEVEL >= 2) {
+						Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
+					}
+					emlGetMem(response, receivedCmd[1], 1);
+					AppendCrc14443a(response, 16);
+					mf_crypto1_encrypt(pcs, response, 18, &par);
+					EmSendCmdPar(response, 18, par);
+					numReads++;
+					if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
+						Dbprintf("%d reads done, exiting", numReads);
+						finished = true;
+					}
+					break;
+				}
+				// write block
+				if (receivedCmd[0] == 0xA0) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					cardSTATE = MFEMUL_WRITEBL2;
+					cardWRBL = receivedCmd[1];
+					break;
+				}
+				// increment, decrement, restore
+				if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+					if (emlCheckValBl(receivedCmd[1])) {
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						break;
+					}
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					if (receivedCmd[0] == 0xC1)
+						cardSTATE = MFEMUL_INTREG_INC;
+					if (receivedCmd[0] == 0xC0)
+						cardSTATE = MFEMUL_INTREG_DEC;
+					if (receivedCmd[0] == 0xC2)
+						cardSTATE = MFEMUL_INTREG_REST;
+					cardWRBL = receivedCmd[1];
+					break;
+				}
+				// transfer
+				if (receivedCmd[0] == 0xB0) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+					if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					else
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					break;
+				}
+				// halt
+				if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
+					LED_B_OFF();
+					LED_C_OFF();
+					cardSTATE = MFEMUL_HALTED;
+					if (MF_DBGLEVEL >= 4)	Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+					break;
+				}
+				// RATS
+				if (receivedCmd[0] == 0xe0) {//RATS
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					break;
+				}
+				// command not allowed
+				if (MF_DBGLEVEL >= 4)	Dbprintf("Received command not allowed, nacking");
+				EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+				break;
+			}
+			case MFEMUL_WRITEBL2:{
+				if (len == 18){
+					mf_crypto1_decrypt(pcs, receivedCmd, len);
+					emlSetMem(receivedCmd, cardWRBL, 1);
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					cardSTATE = MFEMUL_WORK;
+				} else {
+					cardSTATE_TO_IDLE();
+					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+					LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+				}
+				break;
+			}
+			
+			case MFEMUL_INTREG_INC:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				} 
+				LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+				cardINTREG = cardINTREG + ans;
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+			case MFEMUL_INTREG_DEC:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+				cardINTREG = cardINTREG - ans;
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+			case MFEMUL_INTREG_REST:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
+				LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+		}
+	}
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LEDsoff();
+
+	if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
+	{
+		//May just aswell send the collected ar_nr in the response aswell
+		cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
+	}
+
+	if(flags & FLAG_NR_AR_ATTACK)
+	{
+		if(ar_nr_collected > 1) {
+			Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
+			Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
+					 ar_nr_responses[0], // UID
+					ar_nr_responses[1], //NT
+					ar_nr_responses[2], //AR1
+					ar_nr_responses[3], //NR1
+					ar_nr_responses[6], //AR2
+					ar_nr_responses[7] //NR2
+					);
+		} else {
+			Dbprintf("Failed to obtain two AR/NR pairs!");
+			if(ar_nr_collected >0) {
+				Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
+						ar_nr_responses[0], // UID
+						ar_nr_responses[1], //NT
+						ar_nr_responses[2], //AR1
+						ar_nr_responses[3] //NR1
+						);
+			}
+		}
+	}
+	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, traceLen);
+}
+
+
+
+//-----------------------------------------------------------------------------
+// MIFARE sniffer. 
+// 
+//-----------------------------------------------------------------------------
+void RAMFUNC SniffMifare(uint8_t param) {
+	// param:
+	// bit 0 - trigger from first card answer
+	// bit 1 - trigger from first reader 7-bit request
+
+	// C(red) A(yellow) B(green)
+	LEDsoff();
+	// init trace buffer
+    iso14a_clear_trace();
+
+	// The command (reader -> tag) that we're receiving.
+	// The length of a received command will in most cases be no more than 18 bytes.
+	// So 32 should be enough!
+	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	// The response (tag -> reader) that we're receiving.
+	uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
+
+	// As we receive stuff, we copy it from receivedCmd or receivedResponse
+	// into trace, along with its length and other annotations.
+	//uint8_t *trace = (uint8_t *)BigBuf;
+	
+	// The DMA buffer, used to stream samples from the FPGA
+	uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
+	uint8_t *data = dmaBuf;
+	uint8_t previous_data = 0;
+	int maxDataLen = 0;
+	int dataLen = 0;
+	bool ReaderIsActive = FALSE;
+	bool TagIsActive = FALSE;
+
+	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
+	// Set up the demodulator for tag -> reader responses.
+	Demod.output = receivedResponse;
+
+	// Set up the demodulator for the reader -> tag commands
+	Uart.output = receivedCmd;
+
+	// Setup for the DMA.
+	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
+
+	LED_D_OFF();
+	
+	// init sniffer
+	MfSniffInit();
+
+	// And now we loop, receiving samples.
+	for(uint32_t sniffCounter = 0; TRUE; ) {
+	
+		if(BUTTON_PRESS()) {
+			DbpString("cancelled by button");
+			break;
+		}
+
+		LED_A_ON();
+		WDT_HIT();
+		
+ 		if ((sniffCounter & 0x0000FFFF) == 0) {	// from time to time
+			// check if a transaction is completed (timeout after 2000ms).
+			// if yes, stop the DMA transfer and send what we have so far to the client
+			if (MfSniffSend(2000)) {			
+				// Reset everything - we missed some sniffed data anyway while the DMA was stopped
+				sniffCounter = 0;
+				data = dmaBuf;
+				maxDataLen = 0;
+				ReaderIsActive = FALSE;
+				TagIsActive = FALSE;
+				FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
+			}
+		}
+		
+		int register readBufDataP = data - dmaBuf;	// number of bytes we have processed so far
+		int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
+		if (readBufDataP <= dmaBufDataP){			// we are processing the same block of data which is currently being transferred
+			dataLen = dmaBufDataP - readBufDataP;	// number of bytes still to be processed
+		} else {									
+			dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
+		}
+		// test for length of buffer
+		if(dataLen > maxDataLen) {					// we are more behind than ever...
+			maxDataLen = dataLen;					
+			if(dataLen > 400) {
+				Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
+				break;
+			}
+		}
+		if(dataLen < 1) continue;
+
+		// primary buffer was stopped ( <-- we lost data!
+		if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+			AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+			Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
+		}
+		// secondary buffer sets as primary, secondary buffer was stopped
+		if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+		}
+
+		LED_A_OFF();
+		
+		if (sniffCounter & 0x01) {
+
+			if(!TagIsActive) {		// no need to try decoding tag data if the reader is sending
+				uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+				if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
+					LED_C_INV();
+					if (MfSniffLogic(receivedCmd, Uart.len, Uart.parityBits, Uart.bitCount, TRUE)) break;
+
+					/* And ready to receive another command. */
+					UartReset();
+					
+					/* And also reset the demod code */
+					DemodReset();
+				}
+				ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+			}
+			
+			if(!ReaderIsActive) {		// no need to try decoding tag data if the reader is sending
+				uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+				if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
+					LED_C_INV();
+
+					if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
+
+					// And ready to receive another response.
+					DemodReset();
+				}
+				TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+			}
+		}
+
+		previous_data = *data;
+		sniffCounter++;
+		data++;
+		if(data == dmaBuf + DMA_BUFFER_SIZE) {
+			data = dmaBuf;
+		}
+
+	} // main cycle
+
+	DbpString("COMMAND FINISHED");
+
+	FpgaDisableSscDma();
+	MfSniffEnd();
+	
+	Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
+	LEDsoff();
+}