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[proxmark3-svn] / armsrc / iso14443b.c
diff --git a/armsrc/iso14443b.c b/armsrc/iso14443b.c
index fb8b4d66bd9e9aa67386cf156687e688f9eb9839..0c887a2539b00fafdcc8b9ecaa8c6d3e3b74f862 100644 (file)
--- a/armsrc/iso14443b.c
+++ b/armsrc/iso14443b.c
@@ -8,20 +8,45 @@
 // Routines to support ISO 14443B. This includes both the reader software and
 // the `fake tag' modes.
 //-----------------------------------------------------------------------------
 // Routines to support ISO 14443B. This includes both the reader software and
 // the `fake tag' modes.
 //-----------------------------------------------------------------------------
+#include "iso14443b.h"
 
 
-#include "proxmark3.h"
-#include "apps.h"
-#include "util.h"
-#include "string.h"
-#include "iso14443crc.h"
-#include "common.h"
-#define RECEIVE_SAMPLES_TIMEOUT 600000
+#define RECEIVE_SAMPLES_TIMEOUT 50000
 #define ISO14443B_DMA_BUFFER_SIZE 256
 
 #define ISO14443B_DMA_BUFFER_SIZE 256
 
+// Guard Time (per 14443-2)
+#define TR0 0  
+// Synchronization time (per 14443-2)
+#define TR1 0
+// Frame Delay Time PICC to PCD  (per 14443-3 Amendment 1)
+#define TR2 0
 
 
-// PCB Block number for APDUs
+// 4sample
+//#define SEND4STUFFBIT(x) ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);
+#define SEND4STUFFBIT(x) ToSendStuffBit(x);
+
+static void switch_off(void);
+
+// the block number for the ISO14443-4 PCB  (used with APDUs)
 static uint8_t pcb_blocknum = 0;
 
 static uint8_t pcb_blocknum = 0;
 
+static uint32_t iso14b_timeout = RECEIVE_SAMPLES_TIMEOUT;
+// param timeout is in ftw_ 
+void iso14b_set_timeout(uint32_t timeout) {
+       // 9.4395us = 1etu.
+       // clock is about 1.5 us
+       iso14b_timeout = timeout;
+       if(MF_DBGLEVEL >= 2) Dbprintf("ISO14443B Timeout set to %ld fwt", iso14b_timeout);
+}
+
+static void switch_off(void){  
+       if (MF_DBGLEVEL > 3) Dbprintf("switch_off");
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelay(100);
+       FpgaDisableSscDma();
+       set_tracing(FALSE);
+       LEDsoff();      
+}
+
 //=============================================================================
 // An ISO 14443 Type B tag. We listen for commands from the reader, using
 // a UART kind of thing that's implemented in software. When we get a
 //=============================================================================
 // An ISO 14443 Type B tag. We listen for commands from the reader, using
 // a UART kind of thing that's implemented in software. When we get a
@@ -30,111 +55,215 @@ static uint8_t pcb_blocknum = 0;
 // a response.
 //=============================================================================
 
 // a response.
 //=============================================================================
 
+
+//-----------------------------------------------------------------------------
+// The software UART that receives commands from the reader, and its state variables.
+//-----------------------------------------------------------------------------
+static struct {
+       enum {
+               STATE_UNSYNCD,
+               STATE_GOT_FALLING_EDGE_OF_SOF,
+               STATE_AWAITING_START_BIT,
+               STATE_RECEIVING_DATA
+       }       state;
+       uint16_t shiftReg;
+       int      bitCnt;
+       int      byteCnt;
+       int      byteCntMax;
+       int      posCnt;
+       uint8_t  *output;
+} Uart;
+
+static void UartReset() {
+       Uart.state = STATE_UNSYNCD;
+       Uart.shiftReg = 0;
+       Uart.bitCnt = 0;
+       Uart.byteCnt = 0;
+       Uart.byteCntMax = MAX_FRAME_SIZE;
+       Uart.posCnt = 0;
+}
+
+static void UartInit(uint8_t *data) {
+       Uart.output = data;
+       UartReset();
+//             memset(Uart.output, 0x00, MAX_FRAME_SIZE);
+}
+
+//-----------------------------------------------------------------------------
+// The software Demod that receives commands from the tag, and its state variables.
+//-----------------------------------------------------------------------------
+static struct {
+       enum {
+               DEMOD_UNSYNCD,
+               DEMOD_PHASE_REF_TRAINING,
+               DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
+               DEMOD_GOT_FALLING_EDGE_OF_SOF,
+               DEMOD_AWAITING_START_BIT,
+               DEMOD_RECEIVING_DATA
+       }       state;
+       uint16_t bitCount;
+       int      posCount;
+       int      thisBit;
+/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
+       int     metric;
+       int     metricN;
+*/
+       uint16_t shiftReg;
+       uint8_t  *output;
+       uint16_t len;
+       int      sumI;
+       int      sumQ;
+       uint32_t startTime, endTime;
+} Demod;
+
+// Clear out the state of the "UART" that receives from the tag.
+static void DemodReset() {
+       Demod.state = DEMOD_UNSYNCD;
+       Demod.bitCount = 0;
+       Demod.posCount = 0;
+       Demod.thisBit = 0;
+       Demod.shiftReg = 0;
+       Demod.len = 0;
+       Demod.sumI = 0;
+       Demod.sumQ = 0;
+       Demod.startTime = 0;
+       Demod.endTime = 0;      
+}
+
+static void DemodInit(uint8_t *data) {
+       Demod.output = data;
+       DemodReset();
+       //      memset(Demod.output, 0x00, MAX_FRAME_SIZE); 
+}
+
+void AppendCrc14443b(uint8_t* data, int len) {
+       ComputeCrc14443(CRC_14443_B, data, len, data+len, data+len+1);
+}
+
 //-----------------------------------------------------------------------------
 // Code up a string of octets at layer 2 (including CRC, we don't generate
 // that here) so that they can be transmitted to the reader. Doesn't transmit
 // them yet, just leaves them ready to send in ToSend[].
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
 // Code up a string of octets at layer 2 (including CRC, we don't generate
 // that here) so that they can be transmitted to the reader. Doesn't transmit
 // them yet, just leaves them ready to send in ToSend[].
 //-----------------------------------------------------------------------------
-static void CodeIso14443bAsTag(const uint8_t *cmd, int len)
-{
-       int i;
-
+static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
+       /* ISO 14443 B
+       *
+       * Reader to card | ASK  - Amplitude Shift Keying Modulation (PCD to PICC for Type B) (NRZ-L encodig)
+       * Card to reader | BPSK - Binary Phase Shift Keying Modulation, (PICC to PCD for Type B)
+       *
+       * fc - carrier frequency 13.56mHz
+       * TR0 - Guard Time per 14443-2
+       * TR1 - Synchronization Time per 14443-2
+       * TR2 - PICC to PCD Frame Delay Time (per 14443-3 Amendment 1)
+       *
+       * Elementary Time Unit (ETU) is
+       * - 128 Carrier Cycles (9.4395 µS) = 8 Subcarrier Units 
+       * - 1 ETU = 1 bit
+       * - 10 ETU = 1 startbit, 8 databits, 1 stopbit (10bits length)
+       * - startbit is a 0
+       * - stopbit is a 1
+       *
+       * Start of frame (SOF) is
+       * - [10-11] ETU of ZEROS, unmodulated time
+       * - [2-3] ETU of ONES,  
+       *
+       * End of frame (EOF) is
+       * - [10-11] ETU of ZEROS, unmodulated time
+       *
+       *  -TO VERIFY THIS BELOW-
+       * The mode FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK which we use to simulate tag
+       * works like this:  
+       * - A 1-bit input to the FPGA becomes 8 pulses at 847.5kHz (9.44µS)
+       * - A 0-bit input to the FPGA becomes an unmodulated time of 9.44µS
+       *
+       *
+       * 
+       * Card sends data ub 847.e kHz subcarrier
+       * 848k = 9.44µS  = 128 fc
+       * 424k = 18.88µS = 256 fc
+       * 212k = 37.76µS = 512 fc
+       * 106k = 75.52µS = 1024 fc
+       *
+       *  Reader data transmission:
+       *   - no modulation ONES
+       *   - SOF
+       *   - Command, data and CRC_B
+       *   - EOF
+       *   - no modulation ONES
+       *
+       *  Card data transmission
+       *   - TR1
+       *   - SOF
+       *   - data  (each bytes is:  1startbit,8bits, 1stopbit)
+       *   - CRC_B
+       *   - EOF
+       *
+       * FPGA implementation :
+       * At this point only Type A is implemented. This means that we are using a
+       * bit rate of 106 kbit/s, or fc/128. Oversample by 4, which ought to make
+       * things practical for the ARM (fc/32, 423.8 kbits/s, ~50 kbytes/s)
+       *
+       */
+       
+       // ToSendStuffBit,  40 calls
+       // 1 ETU = 1startbit, 1stopbit, 8databits == 10bits.
+       // 1 ETU = 10 * 4 == 40 stuffbits ( ETU_TAG_BIT )
+       int i,j;
+       uint8_t b;
+       
        ToSendReset();
 
        // Transmit a burst of ones, as the initial thing that lets the
        ToSendReset();
 
        // Transmit a burst of ones, as the initial thing that lets the
-       // reader get phase sync. This (TR1) must be > 80/fs, per spec,
-       // but tag that I've tried (a Paypass) exceeds that by a fair bit,
-       // so I will too.
-       for(i = 0; i < 20; i++) {
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-       }
+       // reader get phase sync. 
+       // This loop is TR1, per specification
+       // TR1 minimum must be > 80/fs
+       // TR1 maximum 200/fs 
+       // 80/fs < TR1 < 200/fs
+       // 10 ETU < TR1 < 24 ETU
 
        // Send SOF.
 
        // Send SOF.
-       for(i = 0; i < 10; i++) {
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-       }
-       for(i = 0; i < 2; i++) {
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-       }
-
-       for(i = 0; i < len; i++) {
-               int j;
-               uint8_t b = cmd[i];
-
+       // 10-11 ETU * 4times samples ZEROS
+       for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
+       
+       // 2-3 ETU * 4times samples ONES
+       for(i = 0; i < 3; i++)  { SEND4STUFFBIT(1); }
+       
+       // data
+       for(i = 0; i < len; ++i) {
+               
                // Start bit
                // Start bit
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
+               SEND4STUFFBIT(0);
 
                // Data bits
 
                // Data bits
-               for(j = 0; j < 8; j++) {
-                       if(b & 1) {
-                               ToSendStuffBit(1);
-                               ToSendStuffBit(1);
-                               ToSendStuffBit(1);
-                               ToSendStuffBit(1);
+               b = cmd[i];
+               for(j = 0; j < 8; ++j) {
+                       if(b & 1) { 
+                               SEND4STUFFBIT(1); 
                        } else {
                        } else {
-                               ToSendStuffBit(0);
-                               ToSendStuffBit(0);
-                               ToSendStuffBit(0);
-                               ToSendStuffBit(0);
+                               SEND4STUFFBIT(0);
                        }
                        b >>= 1;
                }
 
                // Stop bit
                        }
                        b >>= 1;
                }
 
                // Stop bit
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
+               SEND4STUFFBIT(1);
+               
+               // Extra Guard bit
+               // For PICC it ranges 0-18us (1etu = 9us)
+               SEND4STUFFBIT(1);
        }
 
        // Send EOF.
        }
 
        // Send EOF.
-       for(i = 0; i < 10; i++) {
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-               ToSendStuffBit(0);
-       }
-       for(i = 0; i < 2; i++) {
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-               ToSendStuffBit(1);
-       }
-
+       // 10-11 ETU * 4 sample rate = ZEROS
+       for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
+       
+       // why this?
+       for(i = 0; i < 40; i++) { SEND4STUFFBIT(1); }
+       
        // Convert from last byte pos to length
        // Convert from last byte pos to length
-       ToSendMax++;
+       ++ToSendMax;
 }
 
 }
 
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
-//-----------------------------------------------------------------------------
-static struct {
-       enum {
-               STATE_UNSYNCD,
-               STATE_GOT_FALLING_EDGE_OF_SOF,
-               STATE_AWAITING_START_BIT,
-               STATE_RECEIVING_DATA
-       }       state;
-       uint16_t    shiftReg;
-       int     bitCnt;
-       int     byteCnt;
-       int     byteCntMax;
-       int     posCnt;
-       uint8_t   *output;
-} Uart;
 
 /* Receive & handle a bit coming from the reader.
  *
 
 /* Receive & handle a bit coming from the reader.
  *
@@ -148,13 +277,11 @@ static struct {
  * Returns: true if we received a EOF
  *          false if we are still waiting for some more
  */
  * Returns: true if we received a EOF
  *          false if we are still waiting for some more
  */
-static RAMFUNC int Handle14443bUartBit(uint8_t bit)
-{
+static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
        switch(Uart.state) {
                case STATE_UNSYNCD:
                        if(!bit) {
        switch(Uart.state) {
                case STATE_UNSYNCD:
                        if(!bit) {
-                               // we went low, so this could be the beginning
-                               // of an SOF
+                               // we went low, so this could be the beginning of an SOF
                                Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
                                Uart.posCnt = 0;
                                Uart.bitCnt = 0;
                                Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
                                Uart.posCnt = 0;
                                Uart.bitCnt = 0;
@@ -262,25 +389,6 @@ static RAMFUNC int Handle14443bUartBit(uint8_t bit)
        return FALSE;
 }
 
        return FALSE;
 }
 
-
-static void UartReset()
-{
-       Uart.byteCntMax = MAX_FRAME_SIZE;
-       Uart.state = STATE_UNSYNCD;
-       Uart.byteCnt = 0;
-       Uart.bitCnt = 0;
-       Uart.posCnt = 0;
-       memset(Uart.output, 0x00, MAX_FRAME_SIZE);
-}
-
-
-static void UartInit(uint8_t *data)
-{
-       Uart.output = data;
-       UartReset();
-}
-
-
 //-----------------------------------------------------------------------------
 // Receive a command (from the reader to us, where we are the simulated tag),
 // and store it in the given buffer, up to the given maximum length. Keeps
 //-----------------------------------------------------------------------------
 // Receive a command (from the reader to us, where we are the simulated tag),
 // and store it in the given buffer, up to the given maximum length. Keeps
@@ -290,195 +398,270 @@ static void UartInit(uint8_t *data)
 // Assume that we're called with the SSC (to the FPGA) and ADC path set
 // correctly.
 //-----------------------------------------------------------------------------
 // Assume that we're called with the SSC (to the FPGA) and ADC path set
 // correctly.
 //-----------------------------------------------------------------------------
-static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len)
-{
+static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
        // Set FPGA mode to "simulated ISO 14443B 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_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
        // Set FPGA mode to "simulated ISO 14443B 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_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
+               
+       StartCountSspClk();
+       
+       volatile uint8_t b;
 
 
+       // clear receiving shift register and holding register
+       // What does this loop do? Is it TR1?
+       for(uint8_t c = 0; c < 10;) {
+               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       AT91C_BASE_SSC->SSC_THR = 0xFF;
+                       ++c;
+               }
+       }
+       
        // Now run a `software UART' on the stream of incoming samples.
        UartInit(received);
 
        // Now run a `software UART' on the stream of incoming samples.
        UartInit(received);
 
-       for(;;) {
+       b = 0;
+       uint8_t mask;
+       while( !BUTTON_PRESS() ) {
                WDT_HIT();
 
                WDT_HIT();
 
-               if(BUTTON_PRESS()) return FALSE;
-
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       for(uint8_t mask = 0x80; mask != 0x00; mask >>= 1) {
-                               if(Handle14443bUartBit(b & mask)) {
+               if ( AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY ) {
+                       b = (uint8_t) AT91C_BASE_SSC->SSC_RHR;
+                       for ( mask = 0x80; mask != 0; mask >>= 1) {
+                               if ( Handle14443bReaderUartBit(b & mask)) {
                                        *len = Uart.byteCnt;
                                        return TRUE;
                                }
                        }
                }
                                        *len = Uart.byteCnt;
                                        return TRUE;
                                }
                        }
                }
+       }       
+       return FALSE;
+}
+
+void ClearFpgaShiftingRegisters(void){
+
+       volatile uint8_t b;
+
+       // 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 (uint8_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;
        }
        
        }
        
-       return FALSE;
+       // Clear TXRDY:
+       AT91C_BASE_SSC->SSC_THR = 0xFF;
 }
 
 }
 
+void WaitForFpgaDelayQueueIsEmpty( uint16_t delay ){
+       // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
+       uint8_t fpga_queued_bits = delay >> 3;  // twich /8 ??   >>3, 
+       for (uint8_t i = 0; i <= fpga_queued_bits/8 + 1; ) {
+               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       AT91C_BASE_SSC->SSC_THR = 0xFF;
+                       i++;
+               }
+       }
+}
+
+static void TransmitFor14443b_AsTag( uint8_t *response, uint16_t len) {
+
+               // Signal field is off with the appropriate LED
+               LED_D_OFF();
+               uint16_t fpgasendQueueDelay = 0;
+               
+               // Modulate BPSK
+               FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK);
+               
+               ClearFpgaShiftingRegisters();
+               
+               FpgaSetupSsc();
+
+               // Transmit the response.
+               for(uint16_t i = 0; i < len;) {
+                       if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+                               AT91C_BASE_SSC->SSC_THR = response[++i];
+                               fpgasendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       }
+               }
+               
+               WaitForFpgaDelayQueueIsEmpty(fpgasendQueueDelay);
+}      
 //-----------------------------------------------------------------------------
 // Main loop of simulated tag: receive commands from reader, decide what
 // response to send, and send it.
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
 // Main loop of simulated tag: receive commands from reader, decide what
 // response to send, and send it.
 //-----------------------------------------------------------------------------
-void SimulateIso14443bTag(void)
-{
-       // the only commands we understand is WUPB, AFI=0, Select All, N=1:
-       static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; // WUPB
-       // ... and REQB, AFI=0, Normal Request, N=1:
-       static const uint8_t cmd2[] = { 0x05, 0x00, 0x00, 0x71, 0xFF }; // REQB
-       // ... and HLTB
-       static const uint8_t cmd3[] = { 0x50, 0xff, 0xff, 0xff, 0xff }; // HLTB
-       // ... and ATTRIB
-       static const uint8_t cmd4[] = { 0x1D, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
-
-       // ... and we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
-       // supports only 106kBit/s in both directions, max frame size = 32Bytes,
-       // supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
-       static const uint8_t response1[] = {
-               0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22,
-               0x00, 0x21, 0x85, 0x5e, 0xd7
-       };
-       // response to HLTB and ATTRIB
-       static const uint8_t response2[] = {0x00, 0x78, 0xF0};
+void SimulateIso14443bTag(uint32_t pupi) {
 
 
-       uint8_t parity[MAX_PARITY_SIZE];
-                               
+       ///////////// setup device.
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
-       clear_trace();
-       set_tracing(TRUE);
-
-       const uint8_t *resp;
-       uint8_t *respCode;
-       uint16_t respLen, respCodeLen;
-
        // allocate command receive buffer
        BigBuf_free();
        // allocate command receive buffer
        BigBuf_free();
-       uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
-
-       uint16_t len;
-       uint16_t cmdsRecvd = 0;
-
-       // prepare the (only one) tag answer:
-       CodeIso14443bAsTag(response1, sizeof(response1));
-       uint8_t *resp1Code = BigBuf_malloc(ToSendMax);
-       memcpy(resp1Code, ToSend, ToSendMax); 
-       uint16_t resp1CodeLen = ToSendMax;
-
-       // prepare the (other) tag answer:
-       CodeIso14443bAsTag(response2, sizeof(response2));
-       uint8_t *resp2Code = BigBuf_malloc(ToSendMax);
-       memcpy(resp2Code, ToSend, ToSendMax); 
-       uint16_t resp2CodeLen = ToSendMax;
-
-       // We need to listen to the high-frequency, peak-detected path.
+       BigBuf_Clear_ext(false);
+       clear_trace(); //sim
+       set_tracing(TRUE);
+       
+       // connect Demodulated Signal to ADC:
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+       // Set up the synchronous serial port
        FpgaSetupSsc();
        FpgaSetupSsc();
+       /////////////
+
+       uint16_t len, cmdsReceived = 0;
+       int cardSTATE = SIM_NOFIELD;
+       int vHf = 0;    // in mV
+       // uint32_t time_0 = 0;
+       // uint32_t t2r_time = 0;
+       // uint32_t r2t_time = 0;
+       uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);   
+       
+       // the only commands we understand is WUPB, AFI=0, Select All, N=1:
+//     static const uint8_t cmdWUPB[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB
+       // ... and REQB, AFI=0, Normal Request, N=1:
+//     static const uint8_t cmdREQB[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB
+       // ... and ATTRIB
+//     static const uint8_t cmdATTRIB[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
 
 
-       cmdsRecvd = 0;
+       // ... if not PUPI/UID is supplied we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
+       // supports only 106kBit/s in both directions, max frame size = 32Bytes,
+       // supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
+       uint8_t respATQB[] = {  0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 
+                                                       0x22, 0x00, 0x21, 0x85, 0x5e, 0xd7 };
+                                                       
+       // response to HLTB and ATTRIB
+       static const uint8_t respOK[] = {0x00, 0x78, 0xF0};
 
 
-       for(;;) {
+       // ...PUPI/UID supplied from user. Adjust ATQB response accordingly
+       if ( pupi > 0 ) {
+               num_to_bytes(pupi, 4, respATQB+1);
+               ComputeCrc14443(CRC_14443_B, respATQB, 12, respATQB+13, respATQB+14);
+       }
 
 
-               if(!GetIso14443bCommandFromReader(receivedCmd, &len)) {
-               Dbprintf("button pressed, received %d commands", cmdsRecvd);
-               break;
-               }
+       // prepare "ATQB" tag answer (encoded):
+       CodeIso14443bAsTag(respATQB, sizeof(respATQB));
+       uint8_t *encodedATQB = BigBuf_malloc(ToSendMax);
+       uint16_t encodedATQBLen = ToSendMax;
+       memcpy(encodedATQB, ToSend, ToSendMax); 
 
 
-               if (tracing) {
-                       LogTrace(receivedCmd, len, 0, 0, parity, TRUE);
-               }
+       
+       // prepare "OK" tag answer (encoded):
+       CodeIso14443bAsTag(respOK, sizeof(respOK));
+       uint8_t *encodedOK = BigBuf_malloc(ToSendMax);
+       uint16_t encodedOKLen = ToSendMax;      
+       memcpy(encodedOK, ToSend, ToSendMax); 
+       
+       // Simulation loop
+       while (!BUTTON_PRESS() && !usb_poll_validate_length()) {
+               WDT_HIT();
 
 
-               // Good, look at the command now.
-               if ( (len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0)
-                       || (len == sizeof(cmd2) && memcmp(receivedCmd, cmd2, len) == 0) ) {
-                       resp = response1; 
-                       respLen = sizeof(response1);
-                       respCode = resp1Code; 
-                       respCodeLen = resp1CodeLen;
-               } else if ( (len == sizeof(cmd3) && receivedCmd[0] == cmd3[0])
-                       || (len == sizeof(cmd4) && receivedCmd[0] == cmd4[0]) ) {
-                       resp = response2; 
-                       respLen = sizeof(response2);
-                       respCode = resp2Code; 
-                       respCodeLen = resp2CodeLen;
-               } else {
-                       Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd);
-                       // And print whether the CRC fails, just for good measure
-                       uint8_t b1, b2;
-                       if (len >= 3){ // if crc exists
-                       ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
-                       if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
-                               // Not so good, try again.
-                               DbpString("+++CRC fail");
-               
-                       } else {
-                               DbpString("CRC passes");
-                       }
+               // find reader field
+               if (cardSTATE == SIM_NOFIELD) {
+                       vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
+                       if ( vHf > MF_MINFIELDV ) {
+                               cardSTATE = SIM_IDLE; 
+                               LED_A_ON();
                        }
                        }
-                       //get rid of compiler warning
-                       respCodeLen = 0;
-                       resp = response1;
-                       respLen = 0;
-                       respCode = resp1Code;
-                       //don't crash at new command just wait and see if reader will send other new cmds.
-                       //break;
-               }
+               } 
+               if (cardSTATE == SIM_NOFIELD) continue;
 
 
-               cmdsRecvd++;
-
-               if(cmdsRecvd > 0x30) {
-                       DbpString("many commands later...");
+               // Get reader command
+               if (!GetIso14443bCommandFromReader(receivedCmd, &len)) {
+                       Dbprintf("button pressed, received %d commands", cmdsReceived);
                        break;
                }
 
                        break;
                }
 
-               if(respCodeLen <= 0) continue;
-
-               // Modulate BPSK
-               // Signal field is off with the appropriate LED
-               LED_D_OFF();
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK);
-               AT91C_BASE_SSC->SSC_THR = 0xff;
-               FpgaSetupSsc();
-
-               uint8_t c;
-               // clear receiving shift register and holding register
-               while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
-               c = AT91C_BASE_SSC->SSC_RHR; (void) c;
-               while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
-               c = AT91C_BASE_SSC->SSC_RHR; (void) c;
-               
-               // Clear TXRDY:
-               AT91C_BASE_SSC->SSC_THR = 0x00;
-               
-               // Transmit the response.
-               uint16_t FpgaSendQueueDelay = 0;
-               uint16_t i = 0;
-               for(;i < respCodeLen; ) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = respCode[i++];
-                               FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+               // ISO14443-B protocol states:
+               // REQ or WUP request in ANY state 
+               // WUP in HALTED state
+               if (len == 5 ) {
+                               if ( (receivedCmd[0] == ISO14443B_REQB && (receivedCmd[2] & 0x8)== 0x8 && cardSTATE == SIM_HALTED) ||
+                     receivedCmd[0] == ISO14443B_REQB ){
+                               LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);                                             
+                               cardSTATE = SIM_SELECTING;
                        }
                        }
-                               if(BUTTON_PRESS()) break;
                }
                
                }
                
-               // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
-               uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
-               for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = 0x00;
-                               FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                               i++;
+               /*
+               * How should this flow go?
+               *  REQB or WUPB
+               *   send response  ( waiting for Attrib)
+               *  ATTRIB
+               *   send response  ( waiting for commands 7816) 
+               *  HALT
+                   send halt response ( waiting for wupb )
+               */
+               
+               switch(cardSTATE){
+                       case SIM_NOFIELD:
+                       case SIM_HALTED:
+                       case SIM_IDLE:{
+                               LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);   
+                               break;
+                       }
+                       case SIM_SELECTING: {
+                               TransmitFor14443b_AsTag( encodedATQB, encodedATQBLen );
+                               LogTrace(respATQB, sizeof(respATQB), 0, 0, NULL, FALSE);
+                               cardSTATE = SIM_WORK;
+                               break;
+                       }
+                       case SIM_HALTING: {
+                               TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
+                               LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
+                               cardSTATE = SIM_HALTED;
+                               break;
+                       }
+                       case SIM_ACKNOWLEDGE:{
+                               TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
+                               LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
+                               cardSTATE = SIM_IDLE;                   
+                               break;
+                       }
+                       case SIM_WORK:{
+                               if ( len == 7 && receivedCmd[0] == ISO14443B_HALT ) {
+                                       cardSTATE = SIM_HALTED;
+                               } else if ( len == 11 && receivedCmd[0] == ISO14443B_ATTRIB ) {
+                                       cardSTATE = SIM_ACKNOWLEDGE;
+                               } else {
+                                       // Todo:
+                                       // - SLOT MARKER
+                                       // - ISO7816
+                                       // - emulate with a memory dump
+                                       Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsReceived);
+
+                                       // CRC Check
+                                       uint8_t b1, b2;
+                                       if (len >= 3){ // if crc exists
+                                               ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
+                                               if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1])
+                                                       DbpString("+++CRC fail");
+                                               else
+                                                       DbpString("CRC passes");
+                                       }
+                                       cardSTATE = SIM_IDLE; 
+                               }
+                               break;
                        }
                        }
+                       default: break;
+               }
+                       
+               ++cmdsReceived;
+               if(cmdsReceived > 1000) {
+                       DbpString("14B Simulate, 1000 commands later...");
+                       break;
                }
                }
-               
-               // trace the response:
-               if (tracing) LogTrace(resp, respLen, 0, 0, parity, FALSE);                      
        }
        }
-       FpgaDisableSscDma();
+       if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
+       switch_off(); //simulate
 }
 
 //=============================================================================
 }
 
 //=============================================================================
@@ -488,29 +671,6 @@ void SimulateIso14443bTag(void)
 // PC side.
 //=============================================================================
 
 // PC side.
 //=============================================================================
 
-static struct {
-       enum {
-               DEMOD_UNSYNCD,
-               DEMOD_PHASE_REF_TRAINING,
-               DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
-               DEMOD_GOT_FALLING_EDGE_OF_SOF,
-               DEMOD_AWAITING_START_BIT,
-               DEMOD_RECEIVING_DATA
-       }       state;
-       int     bitCount;
-       int     posCount;
-       int     thisBit;
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-       int     metric;
-       int     metricN;
-*/
-       uint16_t    shiftReg;
-       uint8_t   *output;
-       int     len;
-       int     sumI;
-       int     sumQ;
-} Demod;
-
 /*
  * Handles reception of a bit from the tag
  *
 /*
  * Handles reception of a bit from the tag
  *
@@ -525,15 +685,12 @@ static struct {
  *          false if we are still waiting for some more
  *
  */
  *          false if we are still waiting for some more
  *
  */
- #define abs(x) ( ((x)<0) ? -(x) : (x) )
-static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
-{
-       int v = 0;
-       int ai = abs(ci);
-       int aq = abs(cq);
-       int halfci = (ai >> 1);
-       int halfcq = (aq >> 1);
+#ifndef SUBCARRIER_DETECT_THRESHOLD
+# define SUBCARRIER_DETECT_THRESHOLD   8
+#endif
 
 
+static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
+       int v=0;// , myI, myQ = 0;
 // The soft decision on the bit uses an estimate of just the
 // quadrant of the reference angle, not the exact angle.
 #define MAKE_SOFT_DECISION() { \
 // The soft decision on the bit uses an estimate of just the
 // quadrant of the reference angle, not the exact angle.
 #define MAKE_SOFT_DECISION() { \
@@ -549,18 +706,54 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                } \
        }
 
                } \
        }
 
-#define SUBCARRIER_DETECT_THRESHOLD    8
-
+// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
 #define CHECK_FOR_SUBCARRIER() { \
 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
 #define CHECK_FOR_SUBCARRIER() { \
-               v = MAX(ai, aq) + MIN(halfci, halfcq); \
-}
+               if(ci < 0) { \
+                       if(cq < 0) { /* ci < 0, cq < 0 */ \
+                               if (cq < ci) { \
+                                       v = -cq - (ci >> 1); \
+                               } else { \
+                                       v = -ci - (cq >> 1); \
+                               } \
+                       } else {        /* ci < 0, cq >= 0 */ \
+                               if (cq < -ci) { \
+                                       v = -ci + (cq >> 1); \
+                               } else { \
+                                       v = cq - (ci >> 1); \
+                               } \
+                       } \
+               } else { \
+                       if(cq < 0) { /* ci >= 0, cq < 0 */ \
+                               if (-cq < ci) { \
+                                       v = ci - (cq >> 1); \
+                               } else { \
+                                       v = -cq + (ci >> 1); \
+                               } \
+                       } else {        /* ci >= 0, cq >= 0 */ \
+                               if (cq < ci) { \
+                                       v = ci + (cq >> 1); \
+                               } else { \
+                                       v = cq + (ci >> 1); \
+                               } \
+                       } \
+               } \
+       }
 
 
+//note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
+#define CHECK_FOR_SUBCARRIER_un() { \
+               myI = ABS(ci); \
+               myQ = ABS(cq); \
+               v = MAX(myI,myQ) + (MIN(myI,myQ) >> 1); \
+       }
 
        switch(Demod.state) {
                case DEMOD_UNSYNCD:
 
        switch(Demod.state) {
                case DEMOD_UNSYNCD:
+
                        CHECK_FOR_SUBCARRIER();
                        CHECK_FOR_SUBCARRIER();
-                       if(v > SUBCARRIER_DETECT_THRESHOLD) {   // subcarrier detected
+
+                       // subcarrier detected
+                       if(v > SUBCARRIER_DETECT_THRESHOLD) {
                                Demod.state = DEMOD_PHASE_REF_TRAINING;
                                Demod.sumI = ci;
                                Demod.sumQ = cq;
                                Demod.state = DEMOD_PHASE_REF_TRAINING;
                                Demod.sumI = ci;
                                Demod.sumQ = cq;
@@ -570,15 +763,17 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 
                case DEMOD_PHASE_REF_TRAINING:
                        if(Demod.posCount < 8) {
 
                case DEMOD_PHASE_REF_TRAINING:
                        if(Demod.posCount < 8) {
-                       //if(Demod.posCount < 10*2) {
+
                                CHECK_FOR_SUBCARRIER();
                                CHECK_FOR_SUBCARRIER();
+                               
                                if (v > SUBCARRIER_DETECT_THRESHOLD) {
                                        // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
                                        // note: synchronization time > 80 1/fs
                                        Demod.sumI += ci;
                                        Demod.sumQ += cq;
                                if (v > SUBCARRIER_DETECT_THRESHOLD) {
                                        // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
                                        // note: synchronization time > 80 1/fs
                                        Demod.sumI += ci;
                                        Demod.sumQ += cq;
-                                       Demod.posCount++;
-                               } else {                // subcarrier lost
+                                       ++Demod.posCount;
+                               } else {        
+                                       // subcarrier lost
                                        Demod.state = DEMOD_UNSYNCD;
                                }
                        } else {
                                        Demod.state = DEMOD_UNSYNCD;
                                }
                        } else {
@@ -587,37 +782,38 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                        break;
 
                case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
                        break;
 
                case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
+                       
                        MAKE_SOFT_DECISION();
                        MAKE_SOFT_DECISION();
-                       //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
-                       if(v <= 0) {    // logic '0' detected
+                       
+                       if(v < 0) {     // logic '0' detected
                                Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
                                Demod.posCount = 0;     // start of SOF sequence
                        } else {
                                Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
                                Demod.posCount = 0;     // start of SOF sequence
                        } else {
-                               if(Demod.posCount > 25*2) {     // maximum length of TR1 = 200 1/fs
-                                       Demod.state = DEMOD_UNSYNCD;
-                               }
+                               // maximum length of TR1 = 200 1/fs
+                               if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD;
                        }
                        }
-                       Demod.posCount++;
+                       ++Demod.posCount;
                        break;
 
                case DEMOD_GOT_FALLING_EDGE_OF_SOF:
                        break;
 
                case DEMOD_GOT_FALLING_EDGE_OF_SOF:
-                       Demod.posCount++;
+                       ++Demod.posCount;
+                       
                        MAKE_SOFT_DECISION();
                        MAKE_SOFT_DECISION();
+                       
                        if(v > 0) {
                        if(v > 0) {
-                               if(Demod.posCount < 10*2) { // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
+                               // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
+                               if(Demod.posCount < 9*2) { 
                                        Demod.state = DEMOD_UNSYNCD;
                                } else {
                                        LED_C_ON(); // Got SOF
                                        Demod.state = DEMOD_UNSYNCD;
                                } else {
                                        LED_C_ON(); // Got SOF
+                                       Demod.startTime = GetCountSspClk();
                                        Demod.state = DEMOD_AWAITING_START_BIT;
                                        Demod.posCount = 0;
                                        Demod.len = 0;
                                        Demod.state = DEMOD_AWAITING_START_BIT;
                                        Demod.posCount = 0;
                                        Demod.len = 0;
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-                                       Demod.metricN = 0;
-                                       Demod.metric = 0;
-*/
                                }
                        } else {
                                }
                        } else {
-                               if(Demod.posCount > 13*2) { // low phase of SOF too long (> 12 etu)
+                               // low phase of SOF too long (> 12 etu)
+                               if (Demod.posCount > 12*2) { 
                                        Demod.state = DEMOD_UNSYNCD;
                                        LED_C_OFF();
                                }
                                        Demod.state = DEMOD_UNSYNCD;
                                        LED_C_OFF();
                                }
@@ -625,9 +821,11 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                        break;
 
                case DEMOD_AWAITING_START_BIT:
                        break;
 
                case DEMOD_AWAITING_START_BIT:
-                       Demod.posCount++;
+                       ++Demod.posCount;
+                       
                        MAKE_SOFT_DECISION();
                        MAKE_SOFT_DECISION();
-                       if(v > 0) {
+                       
+                       if (v > 0) {
                                if(Demod.posCount > 3*2) {              // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
                                        Demod.state = DEMOD_UNSYNCD;
                                        LED_C_OFF();
                                if(Demod.posCount > 3*2) {              // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
                                        Demod.state = DEMOD_UNSYNCD;
                                        LED_C_OFF();
@@ -642,42 +840,40 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
                        break;
 
                case DEMOD_RECEIVING_DATA:
                        break;
 
                case DEMOD_RECEIVING_DATA:
+                       
                        MAKE_SOFT_DECISION();
                        MAKE_SOFT_DECISION();
-                       if(Demod.posCount == 0) {                       // first half of bit
+
+                       if (Demod.posCount == 0) { 
+                               // first half of bit
                                Demod.thisBit = v;
                                Demod.posCount = 1;
                                Demod.thisBit = v;
                                Demod.posCount = 1;
-                       } else {                                                        // second half of bit
+                       } else {
+                               // second half of bit
                                Demod.thisBit += v;
                                Demod.thisBit += v;
-
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-                               if(Demod.thisBit > 0) {
-                                       Demod.metric += Demod.thisBit;
-                               } else {
-                                       Demod.metric -= Demod.thisBit;
-                               }
-                               (Demod.metricN)++;
-*/                             
-
                                Demod.shiftReg >>= 1;
                                Demod.shiftReg >>= 1;
-                               if(Demod.thisBit > 0) { // logic '1'
-                                       Demod.shiftReg |= 0x200;
-                               }
 
 
-                               Demod.bitCount++;
+                               // logic '1'
+                               if(Demod.thisBit > 0)  Demod.shiftReg |= 0x200;
+
+                               ++Demod.bitCount;
+                               
                                if(Demod.bitCount == 10) {
                                if(Demod.bitCount == 10) {
+                                       
                                        uint16_t s = Demod.shiftReg;
                                        uint16_t s = Demod.shiftReg;
-                                       if((s & 0x200) && !(s & 0x001)) { // stop bit == '1', start bit == '0'
+                                       
+                                       // stop bit == '1', start bit == '0'
+                                       if((s & 0x200) && !(s & 0x001)) { 
                                                uint8_t b = (s >> 1);
                                                Demod.output[Demod.len] = b;
                                                uint8_t b = (s >> 1);
                                                Demod.output[Demod.len] = b;
-                                               Demod.len++;
+                                               ++Demod.len;
                                                Demod.state = DEMOD_AWAITING_START_BIT;
                                        } else {
                                                Demod.state = DEMOD_UNSYNCD;
                                                Demod.state = DEMOD_AWAITING_START_BIT;
                                        } else {
                                                Demod.state = DEMOD_UNSYNCD;
+                                               Demod.endTime = GetCountSspClk();
                                                LED_C_OFF();
                                                LED_C_OFF();
-                                               if(s == 0x000) {
-                                                       // This is EOF (start, stop and all data bits == '0'
-                                                       return TRUE;
-                                               }
+                                               
+                                               // This is EOF (start, stop and all data bits == '0'
+                                               if(s == 0) return TRUE;
                                        }
                                }
                                Demod.posCount = 0;
                                        }
                                }
                                Demod.posCount = 0;
@@ -693,237 +889,212 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 }
 
 
 }
 
 
-static void DemodReset()
-{
-       // Clear out the state of the "UART" that receives from the tag.
-       Demod.len = 0;
-       Demod.state = DEMOD_UNSYNCD;
-       Demod.posCount = 0;
-       Demod.sumI = 0;
-       Demod.sumQ = 0;
-       Demod.bitCount = 0;
-       Demod.thisBit = 0;
-       Demod.shiftReg = 0;
-       memset(Demod.output, 0x00, MAX_FRAME_SIZE);
-}
-
-
-static void DemodInit(uint8_t *data)
-{
-       Demod.output = data;
-       DemodReset();
-}
-
-
 /*
  *  Demodulate the samples we received from the tag, also log to tracebuffer
  *  quiet: set to 'TRUE' to disable debug output
  */
 /*
  *  Demodulate the samples we received from the tag, also log to tracebuffer
  *  quiet: set to 'TRUE' to disable debug output
  */
-static void GetSamplesFor14443bDemod(int n, bool quiet)
-{
-       int max = 0;
+static void GetTagSamplesFor14443bDemod() {
        bool gotFrame = FALSE;
        bool gotFrame = FALSE;
-       int lastRxCounter, ci, cq, samples = 0;
+       int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
+       int max = 0, ci = 0, cq = 0, samples = 0;
+       uint32_t time_0 = 0, time_stop = 0;
 
 
-       // Allocate memory from BigBuf for some buffers
-       // free all previous allocations first
        BigBuf_free();
        BigBuf_free();
-
-       // And put the FPGA in the appropriate mode
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
-
-       // The response (tag -> reader) that we're receiving.
+       
        // Set up the demodulator for tag -> reader responses.
        DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
        
        // The DMA buffer, used to stream samples from the FPGA
        int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
        // Set up the demodulator for tag -> reader responses.
        DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
        
        // The DMA buffer, used to stream samples from the FPGA
        int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
-
+       int8_t *upTo = dmaBuf;
+       
        // Setup and start DMA.
        // Setup and start DMA.
-       FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
+       if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
+               if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting"); 
+               return;
+       }
+       
+       time_0 = GetCountSspClk();
+       
+       // And put the FPGA in the appropriate mode
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
        
        
-       int8_t *upTo = dmaBuf;
-       lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
+       while( !BUTTON_PRESS() ) {
+               WDT_HIT();
 
 
-       // Signal field is ON with the appropriate LED:
-       LED_D_ON();
-       for(;;) {
                int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
                if(behindBy > max) max = behindBy;
 
                int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
                if(behindBy > max) max = behindBy;
 
-               while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1)) > 2) {
+               // rx counter - dma counter? (how much?) & (mod) dma buff / 2.  (since 2bytes at the time is read)
+               while(((lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1)) > 2) {
+
                        ci = upTo[0];
                        cq = upTo[1];
                        upTo += 2;
                        ci = upTo[0];
                        cq = upTo[1];
                        upTo += 2;
+                       samples += 2;
+                       
+                       // restart DMA buffer to receive again.
                        if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
                                upTo = dmaBuf;
                                AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
                                AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
                        }
                        if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
                                upTo = dmaBuf;
                                AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
                                AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
                        }
+                       
                        lastRxCounter -= 2;
                        lastRxCounter -= 2;
-                       if(lastRxCounter <= 0) {
-                               lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
-                       }
+                       if(lastRxCounter <= 0)
+                               lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
 
 
-                       samples += 2;
-
-                       //
-                       gotFrame = Handle14443bSamplesDemod(ci , cq );
-                       if ( gotFrame )
-                               break;
+                       // is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
+                       //gotFrame =  Handle14443bTagSamplesDemod(ci & 0xfe, cq & 0xfe);
+                       gotFrame =  Handle14443bTagSamplesDemod(ci, cq);
+                       if ( gotFrame ) break;
+                       LED_A_INV();
                }
 
                }
 
-               if(samples > n || gotFrame) {
-                       break;
-               }
+               time_stop = GetCountSspClk() - time_0;
+       
+               if(time_stop > iso14b_timeout || gotFrame)      break;
        }
        }
+       
+       FpgaDisableSscDma();
 
 
-       AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
-
-       if (!quiet && Demod.len == 0) {
-               Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
+       if (MF_DBGLEVEL >= 3) {
+               Dbprintf("max behindby = %d, samples = %d, gotFrame = %s, Demod.state = %d, Demod.len = %u",
                        max,
                        samples, 
                        max,
                        samples, 
-                       gotFrame, 
-                       Demod.len, 
-                       Demod.sumI, 
-                       Demod.sumQ
+                       (gotFrame) ? "true" : "false", 
+                       Demod.state,
+                       Demod.len
                );
        }
                );
        }
-
-       //Tracing
-       if (tracing && Demod.len > 0) {
-               uint8_t parity[MAX_PARITY_SIZE];
-               LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
-       }
+       if ( Demod.len > 0 )
+               LogTrace(Demod.output, Demod.len, Demod.startTime, Demod.endTime, NULL, FALSE);
 }
 
 
 //-----------------------------------------------------------------------------
 // Transmit the command (to the tag) that was placed in ToSend[].
 //-----------------------------------------------------------------------------
 }
 
 
 //-----------------------------------------------------------------------------
 // Transmit the command (to the tag) that was placed in ToSend[].
 //-----------------------------------------------------------------------------
-static void TransmitFor14443b(void)
-{
-       int c;
-
-       FpgaSetupSsc();
-       
-       while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-               AT91C_BASE_SSC->SSC_THR = 0xff;
-       }
+static void TransmitFor14443b_AsReader(void) {
 
 
-       // Signal field is ON with the appropriate Red LED
-       LED_D_ON();
-       // Signal we are transmitting with the Green LED
-       LED_B_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
+       SpinDelay(20);
        
        
-       for(c = 0; c < 10;) {
+       int c;  
+       // we could been in following mode:
+       // FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ
+       // if its second call or more
+
+       // What does this loop do? Is it TR1?
+       for(c = 0; c < 10;) {
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       AT91C_BASE_SSC->SSC_THR = 0xff;
-                       c++;
-               }
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-                       (void)r;
+                       AT91C_BASE_SSC->SSC_THR = 0xFF;
+                       ++c;
                }
                }
-               WDT_HIT();
        }
        }
-
-       c = 0;
-       for(;;) {
+       
+       // Send frame loop
+       for(c = 0; c < ToSendMax;) {
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
                        AT91C_BASE_SSC->SSC_THR = ToSend[c];
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
                        AT91C_BASE_SSC->SSC_THR = ToSend[c];
-                       c++;
-                       if(c >= ToSendMax) {
-                               break;
-                       }
+                       ++c;
                }
                }
-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                       volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-                       (void)r;
-               }
-               WDT_HIT();
        }
        }
-       LED_B_OFF(); // Finished sending
+       WDT_HIT();
 }
 
 }
 
-
 //-----------------------------------------------------------------------------
 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
 // so that it is ready to transmit to the tag using TransmitFor14443b().
 //-----------------------------------------------------------------------------
 static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
 {
 //-----------------------------------------------------------------------------
 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
 // so that it is ready to transmit to the tag using TransmitFor14443b().
 //-----------------------------------------------------------------------------
 static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
 {
-       int i, j;
+       /*
+       *  Reader data transmission:
+       *   - no modulation ONES
+       *   - SOF
+       *   - Command, data and CRC_B
+       *   - EOF
+       *   - no modulation ONES
+       *
+       *       1 ETU == 1 BIT!
+       *   TR0 - 8 ETUS minimum.
+       */
+       int i;
        uint8_t b;
        uint8_t b;
-
+       
        ToSendReset();
 
        ToSendReset();
 
-       // Establish initial reference level
-       for(i = 0; i < 40; i++) {
-               ToSendStuffBit(1);
-       }
        // Send SOF
        // Send SOF
-       for(i = 0; i < 11; i++) {
+       // 10-11 ETUs of ZERO 
+       for(i = 0; i < 10; ++i) ToSendStuffBit(0);
+       
+       // 2-3 ETUs of ONE
+       ToSendStuffBit(1);
+       ToSendStuffBit(1);
+       ToSendStuffBit(1);
+       
+       // Sending cmd, LSB
+       // from here we add BITS
+       for(i = 0; i < len; ++i) {
+           // Start bit
                ToSendStuffBit(0);
                ToSendStuffBit(0);
-       }
-
-       for(i = 0; i < len; i++) {
-               // Stop bits/EGT
+               // Data bits
+               b = cmd[i];             
+               if (  b & 1 )    ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>1) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>2) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>3) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>4) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>5) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>6) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
+               if ( (b>>7) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);             
+               // Stop bit
                ToSendStuffBit(1);
                ToSendStuffBit(1);
+               // EGT extra guard time
+               // For PCD it ranges 0-57us (1etu = 9us)
                ToSendStuffBit(1);
                ToSendStuffBit(1);
-               // Start bit
-               ToSendStuffBit(0);
-               // Data bits
-               b = cmd[i];
-               for(j = 0; j < 8; j++) {
-                       if(b & 1) {
-                               ToSendStuffBit(1);
-                       } else {
-                               ToSendStuffBit(0);
-                       }
-                       b >>= 1;
-               }
-       }
-       // Send EOF
-       ToSendStuffBit(1);
-       for(i = 0; i < 11; i++) {
-               ToSendStuffBit(0);
-       }
-       for(i = 0; i < 8; i++) {
                ToSendStuffBit(1);
                ToSendStuffBit(1);
-       }
-
-       // And then a little more, to make sure that the last character makes
-       // it out before we switch to rx mode.
-       for(i = 0; i < 10; i++) {
                ToSendStuffBit(1);
        }
                ToSendStuffBit(1);
        }
+       
+       // Send EOF
+       // 10-11 ETUs of ZERO
+       for(i = 0; i < 10; ++i) ToSendStuffBit(0);
 
 
+       // Transition time. TR0 - guard time
+       // 8ETUS minum?
+       // Per specification, Subcarrier must be stopped no later than 2 ETUs after EOF.        
+       for(i = 0; i < 40 ; ++i) ToSendStuffBit(1);
+       
+       // TR1 - Synchronization time
        // Convert from last character reference to length
        // Convert from last character reference to length
-       ToSendMax++;
+       ++ToSendMax;
 }
 
 
 /**
   Convenience function to encode, transmit and trace iso 14443b comms
   **/
 }
 
 
 /**
   Convenience function to encode, transmit and trace iso 14443b comms
   **/
-static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len)
-{
+static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len) {
+       
        CodeIso14443bAsReader(cmd, len);
        CodeIso14443bAsReader(cmd, len);
-       TransmitFor14443b();
-       if (tracing) {
-               uint8_t parity[MAX_PARITY_SIZE];
-               LogTrace(cmd,len, 0, 0, parity, TRUE);
-       }
+       
+       uint32_t time_start = GetCountSspClk();
+
+       TransmitFor14443b_AsReader();
+       
+       if(trigger) LED_A_ON();
+       
+       LogTrace(cmd, len, time_start, GetCountSspClk()-time_start, NULL, TRUE);
 }
 
 /* Sends an APDU to the tag
  * TODO: check CRC and preamble
  */
 }
 
 /* Sends an APDU to the tag
  * TODO: check CRC and preamble
  */
-int iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
+uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
 {
 {
+       uint8_t crc[2] = {0x00, 0x00};
        uint8_t message_frame[message_length + 4];
        // PCB
        message_frame[0] = 0x0A | pcb_blocknum;
        uint8_t message_frame[message_length + 4];
        // PCB
        message_frame[0] = 0x0A | pcb_blocknum;
@@ -935,86 +1106,173 @@ int iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *respo
        // EDC (CRC)
        ComputeCrc14443(CRC_14443_B, message_frame, message_length + 2, &message_frame[message_length + 2], &message_frame[message_length + 3]);
        // send
        // EDC (CRC)
        ComputeCrc14443(CRC_14443_B, message_frame, message_length + 2, &message_frame[message_length + 2], &message_frame[message_length + 3]);
        // send
-       CodeAndTransmit14443bAsReader(message_frame, message_length + 4);
+       CodeAndTransmit14443bAsReader(message_frame, message_length + 4); //no
        // get response
        // get response
-       GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT*100, TRUE);
+       GetTagSamplesFor14443bDemod(); //no
        if(Demod.len < 3)
        if(Demod.len < 3)
-       {
                return 0;
                return 0;
-       }
-       // TODO: Check CRC
+       
+       // VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+       if ( crc[0] != Demod.output[Demod.len-2] || crc[1] != Demod.output[Demod.len-1] )
+               return 0;
+       
        // copy response contents
        if(response != NULL)
        // copy response contents
        if(response != NULL)
-       {
                memcpy(response, Demod.output, Demod.len);
                memcpy(response, Demod.output, Demod.len);
-       }
+
        return Demod.len;
 }
 
        return Demod.len;
 }
 
+/**
+* SRx Initialise.
+*/
+uint8_t iso14443b_select_srx_card(iso14b_card_select_t *card )
+{
+       // INITIATE command: wake up the tag using the INITIATE
+       static const uint8_t init_srx[] = { ISO14443B_INITIATE, 0x00, 0x97, 0x5b };
+       // SELECT command (with space for CRC)
+       uint8_t select_srx[] = { ISO14443B_SELECT, 0x00, 0x00, 0x00};
+       // temp to calc crc.
+       uint8_t crc[2] = {0x00, 0x00};
+       
+       CodeAndTransmit14443bAsReader(init_srx, sizeof(init_srx));
+       GetTagSamplesFor14443bDemod(); //no
+
+       if (Demod.len == 0) return 2;
+
+       // Randomly generated Chip ID   
+       if (card) card->chipid = Demod.output[0];
+       
+       select_srx[1] = Demod.output[0];
+       
+       ComputeCrc14443(CRC_14443_B, select_srx, 2, &select_srx[2], &select_srx[3]);
+       CodeAndTransmit14443bAsReader(select_srx, sizeof(select_srx));
+       GetTagSamplesFor14443bDemod(); //no
+       
+       if (Demod.len != 3)     return 2;
+       
+       // Check the CRC of the answer:
+       ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2 , &crc[0], &crc[1]);
+       if(crc[0] != Demod.output[1] || crc[1] != Demod.output[2]) return 3;
+       
+       // Check response from the tag: should be the same UID as the command we just sent:
+       if (select_srx[1] != Demod.output[0]) return 1;
+
+       // First get the tag's UID:
+       select_srx[0] = ISO14443B_GET_UID;
+
+       ComputeCrc14443(CRC_14443_B, select_srx, 1 , &select_srx[1], &select_srx[2]);
+       CodeAndTransmit14443bAsReader(select_srx, 3); // Only first three bytes for this one
+       GetTagSamplesFor14443bDemod(); //no
+
+       if (Demod.len != 10) return 2;
+       
+       // The check the CRC of the answer
+       ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+       if(crc[0] != Demod.output[8] || crc[1] != Demod.output[9]) return 3;
+
+       if (card) {
+               card->uidlen = 8;
+               memcpy(card->uid, Demod.output, 8);
+       }
+
+       return 0;
+}
 /* Perform the ISO 14443 B Card Selection procedure
  * Currently does NOT do any collision handling.
  * It expects 0-1 cards in the device's range.
  * TODO: Support multiple cards (perform anticollision)
  * TODO: Verify CRC checksums
  */
 /* Perform the ISO 14443 B Card Selection procedure
  * Currently does NOT do any collision handling.
  * It expects 0-1 cards in the device's range.
  * TODO: Support multiple cards (perform anticollision)
  * TODO: Verify CRC checksums
  */
-int iso14443b_select_card()
+uint8_t iso14443b_select_card(iso14b_card_select_t *card )
 {
        // WUPB command (including CRC)
        // Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
 {
        // WUPB command (including CRC)
        // Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
-       static const uint8_t wupb[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
+       static const uint8_t wupb[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 };
        // ATTRIB command (with space for CRC)
        // ATTRIB command (with space for CRC)
-       uint8_t attrib[] = { 0x1D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
+       uint8_t attrib[] = { ISO14443B_ATTRIB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
 
 
+       // temp to calc crc.
+       uint8_t crc[2] = {0x00, 0x00};
+       
        // first, wake up the tag
        CodeAndTransmit14443bAsReader(wupb, sizeof(wupb));
        // first, wake up the tag
        CodeAndTransmit14443bAsReader(wupb, sizeof(wupb));
-       GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+       GetTagSamplesFor14443bDemod(); //select_card
+       
        // ATQB too short?
        // ATQB too short?
-       if (Demod.len < 14)
-       {
-               return 2;
+       if (Demod.len < 14) return 2;
+       
+       // VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+       if ( crc[0] != Demod.output[12] || crc[1] != Demod.output[13] )
+               return 3;
+       
+       if (card) {
+               card->uidlen = 4;
+               memcpy(card->uid, Demod.output+1, 4);
+               memcpy(card->atqb, Demod.output+5, 7);
        }
 
        }
 
-    // select the tag
-    // copy the PUPI to ATTRIB
+    // copy the PUPI to ATTRIB  ( PUPI == UID )
     memcpy(attrib + 1, Demod.output + 1, 4);
     memcpy(attrib + 1, Demod.output + 1, 4);
-    /* copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into
-    ATTRIB (Param 3) */
+       
+    // copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into ATTRIB (Param 3)
     attrib[7] = Demod.output[10] & 0x0F;
     ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10);
     attrib[7] = Demod.output[10] & 0x0F;
     ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10);
+
     CodeAndTransmit14443bAsReader(attrib, sizeof(attrib));
     CodeAndTransmit14443bAsReader(attrib, sizeof(attrib));
-    GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+    GetTagSamplesFor14443bDemod();//select_card
+
     // Answer to ATTRIB too short?
     // Answer to ATTRIB too short?
-    if(Demod.len < 3)
-       {
-               return 2;
+    if(Demod.len < 3) return 2;
+
+       // VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+       if ( crc[0] != Demod.output[1] || crc[1] != Demod.output[2] ) 
+               return 3;
+       
+       // CID
+       if (card) card->cid = Demod.output[0];
+       
+       uint8_t fwt = card->atqb[6]>>4;
+       if ( fwt < 16 ){
+               uint32_t fwt_time = (302 << fwt);
+               iso14b_set_timeout( fwt_time);
        }
        // reset PCB block number
        pcb_blocknum = 0;
        }
        // reset PCB block number
        pcb_blocknum = 0;
-       return 1;
+       return 0;
 }
 
 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
 }
 
 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
+// field is setup for "Sending as Reader"
 void iso14443b_setup() {
 void iso14443b_setup() {
-
+       if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Enter");
+       LEDsoff();
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+       //BigBuf_free();
+       //BigBuf_Clear_ext(false);
+       
+       // Initialize Demod and Uart structs
+       DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
+       UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
 
 
-       BigBuf_free();
-       // Set up the synchronous serial port
-       FpgaSetupSsc();
        // connect Demodulated Signal to ADC:
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
        // connect Demodulated Signal to ADC:
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
+       // Set up the synchronous serial port
+       FpgaSetupSsc();
+       
        // Signal field is on with the appropriate LED
        // Signal field is on with the appropriate LED
-    LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
-       
-       //SpinDelay(100);
+       SpinDelay(100);
 
        // Start the timer
 
        // Start the timer
-       //StartCountSspClk();
-
-       DemodReset();
-       UartReset();
+       StartCountSspClk();
+       
+       LED_D_ON();
+       if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Exit");
 }
 
 //-----------------------------------------------------------------------------
 }
 
 //-----------------------------------------------------------------------------
@@ -1026,22 +1284,18 @@ void iso14443b_setup() {
 //
 // I tried to be systematic and check every answer of the tag, every CRC, etc...
 //-----------------------------------------------------------------------------
 //
 // I tried to be systematic and check every answer of the tag, every CRC, etc...
 //-----------------------------------------------------------------------------
-void ReadSTMemoryIso14443b(uint32_t dwLast)
+void ReadSTMemoryIso14443b(uint8_t numofblocks)
 {
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 {
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
-       BigBuf_free();
 
 
-       clear_trace();
+       // Make sure that we start from off, since the tags are stateful;
+       // confusing things will happen if we don't reset them between reads.
+       switch_off();  // before ReadStMemory
+
        set_tracing(TRUE);
 
        uint8_t i = 0x00;
 
        set_tracing(TRUE);
 
        uint8_t i = 0x00;
 
-       // Make sure that we start from off, since the tags are stateful;
-       // confusing things will happen if we don't reset them between reads.
-       LED_D_OFF();
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelay(200);
-
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
        FpgaSetupSsc();
 
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
        FpgaSetupSsc();
 
@@ -1049,15 +1303,16 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
-       SpinDelay(200);
+       SpinDelay(20);
 
        // First command: wake up the tag using the INITIATE command
 
        // First command: wake up the tag using the INITIATE command
-       uint8_t cmd1[] = {0x06, 0x00, 0x97, 0x5b};
-       CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-       GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+       uint8_t cmd1[] = {ISO14443B_INITIATE, 0x00, 0x97, 0x5b};
+       CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
+       GetTagSamplesFor14443bDemod(); // no
 
        if (Demod.len == 0) {
                DbpString("No response from tag");
 
        if (Demod.len == 0) {
                DbpString("No response from tag");
+               set_tracing(FALSE);     
                return;
        } else {
                Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
                return;
        } else {
                Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
@@ -1066,35 +1321,39 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 
        // There is a response, SELECT the uid
        DbpString("Now SELECT tag:");
 
        // There is a response, SELECT the uid
        DbpString("Now SELECT tag:");
-       cmd1[0] = 0x0E; // 0x0E is SELECT
+       cmd1[0] = ISO14443B_SELECT; // 0x0E is SELECT
        cmd1[1] = Demod.output[0];
        ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
        cmd1[1] = Demod.output[0];
        ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
-       CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-       GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+       CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
+       GetTagSamplesFor14443bDemod(); //no
        if (Demod.len != 3) {
                Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
        if (Demod.len != 3) {
                Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
+               set_tracing(FALSE);     
                return;
        }
        // Check the CRC of the answer:
        ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
        if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
                DbpString("CRC Error reading select response.");
                return;
        }
        // Check the CRC of the answer:
        ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
        if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
                DbpString("CRC Error reading select response.");
+               set_tracing(FALSE);     
                return;
        }
        // Check response from the tag: should be the same UID as the command we just sent:
        if (cmd1[1] != Demod.output[0]) {
                Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
                return;
        }
        // Check response from the tag: should be the same UID as the command we just sent:
        if (cmd1[1] != Demod.output[0]) {
                Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
+               set_tracing(FALSE);     
                return;
        }
 
        // Tag is now selected,
        // First get the tag's UID:
                return;
        }
 
        // Tag is now selected,
        // First get the tag's UID:
-       cmd1[0] = 0x0B;
+       cmd1[0] = ISO14443B_GET_UID;
        ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
        ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
-       CodeAndTransmit14443bAsReader(cmd1, 3); // Only first three bytes for this one
-       GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+       CodeAndTransmit14443bAsReader(cmd1, 3); // no --  Only first three bytes for this one
+       GetTagSamplesFor14443bDemod(); //no
        if (Demod.len != 10) {
                Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
        if (Demod.len != 10) {
                Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
+               set_tracing(FALSE);     
                return;
        }
        // The check the CRC of the answer (use cmd1 as temporary variable):
                return;
        }
        // The check the CRC of the answer (use cmd1 as temporary variable):
@@ -1109,22 +1368,24 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
                        (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
 
        // Now loop to read all 16 blocks, address from 0 to last block
                        (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
 
        // Now loop to read all 16 blocks, address from 0 to last block
-       Dbprintf("Tag memory dump, block 0 to %d", dwLast);
+       Dbprintf("Tag memory dump, block 0 to %d", numofblocks);
        cmd1[0] = 0x08;
        i = 0x00;
        cmd1[0] = 0x08;
        i = 0x00;
-       dwLast++;
+       ++numofblocks;
+       
        for (;;) {
        for (;;) {
-                  if (i == dwLast) {
+               if (i == numofblocks) {
                        DbpString("System area block (0xff):");
                        i = 0xff;
                }
                cmd1[1] = i;
                ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
                        DbpString("System area block (0xff):");
                        i = 0xff;
                }
                cmd1[1] = i;
                ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
-               CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-               GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+               CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
+               GetTagSamplesFor14443bDemod(); //no
+               
                if (Demod.len != 6) { // Check if we got an answer from the tag
                if (Demod.len != 6) { // Check if we got an answer from the tag
-               DbpString("Expected 6 bytes from tag, got less...");
-               return;
+                       DbpString("Expected 6 bytes from tag, got less...");
+                       return;
                }
                // The check the CRC of the answer (use cmd1 as temporary variable):
                ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
                }
                // The check the CRC of the answer (use cmd1 as temporary variable):
                ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
@@ -1137,14 +1398,52 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
                Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
                                (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
                                (Demod.output[4]<<8)+Demod.output[5]);
                Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
                                (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
                                (Demod.output[4]<<8)+Demod.output[5]);
-               if (i == 0xff) {
-                       break;
-               }
-               i++;
+
+               if (i == 0xff) break;
+               ++i;
        }
        }
+       
+       set_tracing(FALSE);
 }
 
 
 }
 
 
+static void iso1444b_setup_snoop(void){
+       if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Enter");
+       LEDsoff();
+       FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+       BigBuf_free();
+       BigBuf_Clear_ext(false); 
+       clear_trace();//setup snoop
+       set_tracing(TRUE);
+
+       // Initialize Demod and Uart structs
+       DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
+       UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
+
+       if (MF_DBGLEVEL > 1) {
+               // Print debug information about the buffer sizes
+               Dbprintf("Snooping buffers initialized:");
+               Dbprintf("  Trace: %i bytes", BigBuf_max_traceLen());
+               Dbprintf("  Reader -> tag: %i bytes", MAX_FRAME_SIZE);
+               Dbprintf("  tag -> Reader: %i bytes", MAX_FRAME_SIZE);
+               Dbprintf("  DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE);
+       }
+
+       // connect Demodulated Signal to ADC:
+       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+
+       // Setup for the DMA.
+       FpgaSetupSsc();
+
+       // Set FPGA in the appropriate mode
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);
+       SpinDelay(20);  
+
+       // Start the SSP timer
+       StartCountSspClk();
+       if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Exit");
+}
+
 //=============================================================================
 // Finally, the `sniffer' combines elements from both the reader and
 // simulated tag, to show both sides of the conversation.
 //=============================================================================
 // Finally, the `sniffer' combines elements from both the reader and
 // simulated tag, to show both sides of the conversation.
@@ -1162,182 +1461,237 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
  * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
  * Demodulated samples received - all the rest
  */
  * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
  * Demodulated samples received - all the rest
  */
-void RAMFUNC SnoopIso14443b(void)
-{
+void RAMFUNC SnoopIso14443b(void) {
+
+       uint32_t time_0 = 0, time_start = 0, time_stop = 0;
+       
        // We won't start recording the frames that we acquire until we trigger;
        // a good trigger condition to get started is probably when we see a
        // response from the tag.
        // 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.
-       int triggered = TRUE;                   // TODO: set and evaluate trigger condition
-
-       FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
-       BigBuf_free();
-
-       clear_trace();
-       set_tracing(TRUE);
-
-       // The DMA buffer, used to stream samples from the FPGA
-       int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
-       int lastRxCounter;
-       int8_t *upTo;
+       int triggered = TRUE;                   // TODO: set and evaluate trigger condition     
        int ci, cq;
        int maxBehindBy = 0;
        int ci, cq;
        int maxBehindBy = 0;
-
-       // Count of samples received so far, so that we can include timing
-       // information in the trace buffer.
-       int samples = 0;
-
-       DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
-       UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
-
-       // Print some debug information about the buffer sizes
-       Dbprintf("Snooping buffers initialized:");
-       Dbprintf("  Trace: %i bytes", BigBuf_max_traceLen());
-       Dbprintf("  Reader -> tag: %i bytes", MAX_FRAME_SIZE);
-       Dbprintf("  tag -> Reader: %i bytes", MAX_FRAME_SIZE);
-       Dbprintf("  DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE);
-
-       // Signal field is off, no reader signal, no tag signal
-       LEDsoff();
-
-       // And put the FPGA in the appropriate mode
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);
-       SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-       // Setup for the DMA.
-       FpgaSetupSsc();
-       upTo = dmaBuf;
-       lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
-       FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
-       uint8_t parity[MAX_PARITY_SIZE];
-
+       //int behindBy  = 0;
+       int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
+       
        bool TagIsActive = FALSE;
        bool ReaderIsActive = FALSE;
        bool TagIsActive = FALSE;
        bool ReaderIsActive = FALSE;
+
+       iso1444b_setup_snoop();
+       
+       // The DMA buffer, used to stream samples from the FPGA
+       int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
+       int8_t *upTo = dmaBuf;
+
+       // Setup and start DMA.
+       if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
+               if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting"); 
+               BigBuf_free();
+               return;
+       }
+       
+       time_0 = GetCountSspClk();
                
        // And now we loop, receiving samples.
        for(;;) {
                
        // And now we loop, receiving samples.
        for(;;) {
-               int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
-                                                               (ISO14443B_DMA_BUFFER_SIZE-1);
-               if(behindBy > maxBehindBy) {
-                       maxBehindBy = behindBy;
-               }
 
 
-               if(behindBy < 2) continue;
+               WDT_HIT();
+               
+               int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1);
 
 
+               if ( behindBy > maxBehindBy )
+                       maxBehindBy = behindBy;
+               
+               if ( behindBy < 2 ) continue;
+               
                ci = upTo[0];
                cq = upTo[1];
                upTo += 2;
                ci = upTo[0];
                cq = upTo[1];
                upTo += 2;
+               
                lastRxCounter -= 2;
                lastRxCounter -= 2;
-               if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
+               
+               if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
                        upTo = dmaBuf;
                        lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
                        AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
                        AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
                        WDT_HIT();
                        upTo = dmaBuf;
                        lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
                        AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
                        AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
                        WDT_HIT();
-                       if(behindBy > (9*ISO14443B_DMA_BUFFER_SIZE/10)) { // TODO: understand whether we can increase/decrease as we want or not?
+                       
+                       // TODO: understand whether we can increase/decrease as we want or not?
+                       if ( behindBy > ( 9 * ISO14443B_DMA_BUFFER_SIZE/10) ) { 
                                Dbprintf("blew circular buffer! behindBy=%d", behindBy);
                                break;
                        }
                                Dbprintf("blew circular buffer! behindBy=%d", behindBy);
                                break;
                        }
+                       
                        if(!tracing) {
                        if(!tracing) {
-                               DbpString("Reached trace limit");
+                               DbpString("Trace full");
                                break;
                        }
                                break;
                        }
+                               
                        if(BUTTON_PRESS()) {
                                DbpString("cancelled");
                                break;
                        }
                }
                        if(BUTTON_PRESS()) {
                                DbpString("cancelled");
                                break;
                        }
                }
+               
+               if (!TagIsActive) {             
+               
+                       LED_A_ON();
+                       
+                       // no need to try decoding reader data if the tag is sending
+                       if (Handle14443bReaderUartBit(ci & 0x01)) {
 
 
-               samples += 2;
-
-               if (!TagIsActive) {                                                     // no need to try decoding reader data if the tag is sending
-                       if(Handle14443bUartBit(ci & 0x01)) {
-                       if(triggered && tracing) {
-                                       LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
+                               time_stop = (GetCountSspClk()-time_0);
+                               
+                               if (triggered)
+                                       LogTrace(Uart.output, Uart.byteCnt, time_start, time_stop, NULL, TRUE);
+
+                               /* 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();
+                       } else {
+                               time_start = (GetCountSspClk()-time_0);
                        }
                        }
-                       /* 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();
-               }
-                       if(Handle14443bUartBit(cq & 0x01)) {
-                       if(triggered && tracing) {
-                                       LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
+                       
+                       if (Handle14443bReaderUartBit(cq & 0x01)) {
+                               
+                               time_stop = (GetCountSspClk()-time_0);
+                               
+                               if (triggered)
+                                       LogTrace(Uart.output, Uart.byteCnt, time_start, time_stop, NULL, TRUE);
+
+                                       /* 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();
+                       } else {
+                               time_start = (GetCountSspClk()-time_0);
                        }
                        }
-                       /* 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();
-               }
                        ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
                        ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
+                       LED_A_OFF();
                }
                }
-
-               if(!ReaderIsActive) {                                           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
+               
+               if(!ReaderIsActive) {
+                       // no need to try decoding tag data if the reader is sending - and we cannot afford the time
                        // is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
                        // is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
-                       if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) {
+                       if(Handle14443bTagSamplesDemod(ci & 0xFE, cq & 0xFE)) {
+                               
+                               time_stop = (GetCountSspClk()-time_0);
+                               
+                               LogTrace(Demod.output, Demod.len, time_start, time_stop, NULL, FALSE);
 
 
-                       //Use samples as a time measurement
-                       if(tracing)
-                       {
-                               //uint8_t parity[MAX_PARITY_SIZE];
-                               LogTrace(Demod.output, Demod.len, samples, samples, parity, FALSE);
-                       }
-                       triggered = TRUE;
+                               triggered = TRUE;
 
 
-                       // And ready to receive another response.
-                       DemodReset();
-               }
+                               // And ready to receive another response.
+                               DemodReset();
+                       } else {
+                               time_start = (GetCountSspClk()-time_0);
+                       }
                        TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
                }
                        TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
                }
-
        }
 
        }
 
-       FpgaDisableSscDma();
-       LEDsoff();
-       AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
+       switch_off(); // Snoop
+       
        DbpString("Snoop statistics:");
        Dbprintf("  Max behind by: %i", maxBehindBy);
        DbpString("Snoop statistics:");
        Dbprintf("  Max behind by: %i", maxBehindBy);
-       Dbprintf("  Uart State: %x", Uart.state);
-       Dbprintf("  Uart ByteCnt: %i", Uart.byteCnt);
-       Dbprintf("  Uart ByteCntMax: %i", Uart.byteCntMax);
+       Dbprintf("  Uart State: %x  ByteCount: %i  ByteCountMax: %i", Uart.state,  Uart.byteCnt,  Uart.byteCntMax);
        Dbprintf("  Trace length: %i", BigBuf_get_traceLen());
        Dbprintf("  Trace length: %i", BigBuf_get_traceLen());
+
+       // free mem refs.
+       if ( dmaBuf ) dmaBuf = NULL;
+       if ( upTo )   upTo = NULL;
+       // Uart.byteCntMax  should be set with ATQB value..
 }
 
 }
 
+void iso14b_set_trigger(bool enable) {
+       trigger = enable;
+}
 
 /*
  * Send raw command to tag ISO14443B
  * @Input
 
 /*
  * Send raw command to tag ISO14443B
  * @Input
- * datalen     len of buffer data
- * recv        bool when true wait for data from tag and send to client
- * powerfield  bool leave the field on when true
- * data        buffer with byte to send
+ * param   flags enum ISO14B_COMMAND.  (mifare.h)
+ * len     len of buffer data
+ * data    buffer with bytes to send
  *
  * @Output
  * none
  *
  */
  *
  * @Output
  * none
  *
  */
-void SendRawCommand14443B(uint32_t datalen, uint32_t recv, uint8_t powerfield, uint8_t data[])
+void SendRawCommand14443B_Ex(UsbCommand *c)
 {
 {
-       iso14443b_setup();
+       iso14b_command_t param = c->arg[0];
+       size_t len = c->arg[1] & 0xffff;
+       uint8_t *cmd = c->d.asBytes;
+       uint8_t status = 0;
+       uint32_t sendlen = sizeof(iso14b_card_select_t);
+       uint8_t buf[USB_CMD_DATA_SIZE] = {0x00};
+
+       if (MF_DBGLEVEL > 3) Dbprintf("14b raw: param, %04x", param );
        
        
-       if ( datalen == 0 && recv == 0 && powerfield == 0){
-               
-       } else {                
-               set_tracing(TRUE);
-               CodeAndTransmit14443bAsReader(data, datalen);
+       // turn on trigger (LED_A)
+       if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
+               iso14b_set_trigger(TRUE);
+       
+       if ((param & ISO14B_CONNECT) == ISO14B_CONNECT) {
+               // Make sure that we start from off, since the tags are stateful;
+               // confusing things will happen if we don't reset them between reads.
+               //switch_off();  // before connect in raw
+               iso14443b_setup();
        }
        }
+       
+       set_tracing(TRUE);
 
 
-       if(recv) {
-               GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, FALSE);
-               uint16_t iLen = MIN(Demod.len, USB_CMD_DATA_SIZE);
-               cmd_send(CMD_ACK, iLen, 0, 0, Demod.output, iLen);
+       if ((param & ISO14B_SELECT_STD) == ISO14B_SELECT_STD) {
+               iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
+               status = iso14443b_select_card(card);   
+               cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
+               // 0: OK 2: attrib fail, 3:crc fail,
+               if ( status > 0 ) return;
+       } 
+       
+       if ((param & ISO14B_SELECT_SR) == ISO14B_SELECT_SR) {
+               iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
+               status = iso14443b_select_srx_card(card);
+               cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
+               // 0: OK 2: attrib fail, 3:crc fail,
+               if ( status > 0 ) return;
+       } 
+       
+       if ((param & ISO14B_APDU) == ISO14B_APDU) {
+               status = iso14443b_apdu(cmd, len, buf);
+               cmd_send(CMD_ACK, status, status, 0, buf, status);
        }
        
        }
        
-       if(!powerfield) {
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-               FpgaDisableSscDma();
-               LED_D_OFF();
+       if ((param & ISO14B_RAW) == ISO14B_RAW) {
+               if((param & ISO14B_APPEND_CRC) == ISO14B_APPEND_CRC) {
+                       AppendCrc14443b(cmd, len);
+                       len += 2;
+               }
+       
+               CodeAndTransmit14443bAsReader(cmd, len); // raw         
+               GetTagSamplesFor14443bDemod(); // raw
+               
+               sendlen = MIN(Demod.len, USB_CMD_DATA_SIZE);
+               status =  (Demod.len > 0) ? 0 : 1;
+               cmd_send(CMD_ACK, status, sendlen, 0, Demod.output, sendlen);
        }
        }
-}
-
+       
+       // turn off trigger (LED_A)
+       if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
+               iso14b_set_trigger(FALSE);
+
+       // turn off antenna et al
+       // we don't send a HALT command.
+       if ((param & ISO14B_DISCONNECT) == ISO14B_DISCONNECT) {
+               if (MF_DBGLEVEL > 3) Dbprintf("disconnect");
+               switch_off(); // disconnect raw
+       } else {
+               //FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);              
+       }
+       
+}
\ No newline at end of file
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