]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/lfops.c
Small lf bug fixes and threshold adjustments
[proxmark3-svn] / armsrc / lfops.c
index 5ef01dcf2536d545debd99f82fb2f0c748f69229..f5040850c50cd2b1f93dfdf979bdbd74b463cfe2 100644 (file)
 #include "hitag2.h"
 #include "crc16.h"
 #include "string.h"
+#include "lfdemod.h"
 
-void AcquireRawAdcSamples125k(int at134khz)
-{
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
 
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+/**
+* Does the sample acquisition. If threshold is specified, the actual sampling
+* is not commenced until the threshold has been reached.
+* @param trigger_threshold - the threshold
+* @param silent - is true, now outputs are made. If false, dbprints the status
+*/
+void DoAcquisition125k_internal(int trigger_threshold,bool silent)
+{
+    uint8_t *dest = (uint8_t *)BigBuf;
+    int n = sizeof(BigBuf);
+    int i;
+
+    memset(dest, 0, n);
+    i = 0;
+    for(;;) {
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+            AT91C_BASE_SSC->SSC_THR = 0x43;
+            LED_D_ON();
+        }
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+            LED_D_OFF();
+            if (trigger_threshold != -1 && dest[i] < trigger_threshold)
+                continue;
+            else
+                trigger_threshold = -1;
+            if (++i >= n) break;
+        }
+    }
+    if(!silent)
+    {
+        Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
+                 dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+
+    }
+}
+/**
+* Perform sample aquisition.
+*/
+void DoAcquisition125k(int trigger_threshold)
+{
+    DoAcquisition125k_internal(trigger_threshold, false);
+}
 
-       // Now call the acquisition routine
-       DoAcquisition125k();
+/**
+* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
+* if not already loaded, sets divisor and starts up the antenna.
+* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
+*                                 0 or 95 ==> 125 KHz
+*
+**/
+void LFSetupFPGAForADC(int divisor, bool lf_field)
+{
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
+        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+    else if (divisor == 0)
+        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    else
+        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
+
+    // Connect the A/D to the peak-detected low-frequency path.
+    SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+    // Give it a bit of time for the resonant antenna to settle.
+    SpinDelay(50);
+    // Now set up the SSC to get the ADC samples that are now streaming at us.
+    FpgaSetupSsc();
+}
+/**
+* Initializes the FPGA, and acquires the samples.
+**/
+void AcquireRawAdcSamples125k(int divisor)
+{
+    LFSetupFPGAForADC(divisor, true);
+    // Now call the acquisition routine
+    DoAcquisition125k_internal(-1,false);
 }
+/**
+* Initializes the FPGA for snoop-mode, and acquires the samples.
+**/
 
-// split into two routines so we can avoid timing issues after sending commands //
-void DoAcquisition125k(void)
+void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
 {
-       uint8_t *dest = (uint8_t *)BigBuf;
-       int n = sizeof(BigBuf);
-       int i;
-
-       memset(dest, 0, n);
-       i = 0;
-       for(;;) {
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
-                       AT91C_BASE_SSC->SSC_THR = 0x43;
-                       LED_D_ON();
-               }
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
-                       dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       i++;
-                       LED_D_OFF();
-                       if (i >= n) break;
-               }
-       }
-       Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
-                       dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+    LFSetupFPGAForADC(divisor, false);
+    DoAcquisition125k(trigger_threshold);
 }
 
 void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)
 {
-       int at134khz;
-
-       /* Make sure the tag is reset */
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelay(2500);
-
-       // see if 'h' was specified
-       if (command[strlen((char *) command) - 1] == 'h')
-               at134khz = TRUE;
-       else
-               at134khz = FALSE;
-
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
-       // And a little more time for the tag to fully power up
-       SpinDelay(2000);
-
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
-
-       // now modulate the reader field
-       while(*command != '\0' && *command != ' ') {
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-               LED_D_OFF();
-               SpinDelayUs(delay_off);
-               if (at134khz)
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-               else
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-               LED_D_ON();
-               if(*(command++) == '0')
-                       SpinDelayUs(period_0);
-               else
-                       SpinDelayUs(period_1);
-       }
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       LED_D_OFF();
-       SpinDelayUs(delay_off);
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // now do the read
-       DoAcquisition125k();
+
+    /* Make sure the tag is reset */
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    SpinDelay(2500);
+
+
+    int divisor_used = 95; // 125 KHz
+    // see if 'h' was specified
+
+    if (command[strlen((char *) command) - 1] == 'h')
+        divisor_used = 88; // 134.8 KHz
+
+
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+    // Give it a bit of time for the resonant antenna to settle.
+    SpinDelay(50);
+
+    // And a little more time for the tag to fully power up
+    SpinDelay(2000);
+
+    // Now set up the SSC to get the ADC samples that are now streaming at us.
+    FpgaSetupSsc();
+
+    // now modulate the reader field
+    while(*command != '\0' && *command != ' ') {
+        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+        LED_D_OFF();
+        SpinDelayUs(delay_off);
+        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
+
+        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+        LED_D_ON();
+        if(*(command++) == '0')
+            SpinDelayUs(period_0);
+        else
+            SpinDelayUs(period_1);
+    }
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    LED_D_OFF();
+    SpinDelayUs(delay_off);
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // now do the read
+    DoAcquisition125k(-1);
 }
 
 /* blank r/w tag data stream
@@ -133,229 +169,227 @@ void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1,
 */
 void ReadTItag(void)
 {
-       // some hardcoded initial params
-       // when we read a TI tag we sample the zerocross line at 2Mhz
-       // TI tags modulate a 1 as 16 cycles of 123.2Khz
-       // TI tags modulate a 0 as 16 cycles of 134.2Khz
-       #define FSAMPLE 2000000
-       #define FREQLO 123200
-       #define FREQHI 134200
-
-       signed char *dest = (signed char *)BigBuf;
-       int n = sizeof(BigBuf);
-//     int *dest = GraphBuffer;
-//     int n = GraphTraceLen;
-
-       // 128 bit shift register [shift3:shift2:shift1:shift0]
-       uint32_t shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
-
-       int i, cycles=0, samples=0;
-       // how many sample points fit in 16 cycles of each frequency
-       uint32_t sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
-       // when to tell if we're close enough to one freq or another
-       uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
-
-       // TI tags charge at 134.2Khz
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-
-       // Place FPGA in passthrough mode, in this mode the CROSS_LO line
-       // connects to SSP_DIN and the SSP_DOUT logic level controls
-       // whether we're modulating the antenna (high)
-       // or listening to the antenna (low)
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
-
-       // get TI tag data into the buffer
-       AcquireTiType();
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-
-       for (i=0; i<n-1; i++) {
-               // count cycles by looking for lo to hi zero crossings
-               if ( (dest[i]<0) && (dest[i+1]>0) ) {
-                       cycles++;
-                       // after 16 cycles, measure the frequency
-                       if (cycles>15) {
-                               cycles=0;
-                               samples=i-samples; // number of samples in these 16 cycles
-
-                               // TI bits are coming to us lsb first so shift them
-                               // right through our 128 bit right shift register
-                         shift0 = (shift0>>1) | (shift1 << 31);
-                         shift1 = (shift1>>1) | (shift2 << 31);
-                         shift2 = (shift2>>1) | (shift3 << 31);
-                         shift3 >>= 1;
-
-                               // check if the cycles fall close to the number
-                               // expected for either the low or high frequency
-                               if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {
-                                       // low frequency represents a 1
-                                       shift3 |= (1<<31);
-                               } else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {
-                                       // high frequency represents a 0
-                               } else {
-                                       // probably detected a gay waveform or noise
-                                       // use this as gaydar or discard shift register and start again
-                                       shift3 = shift2 = shift1 = shift0 = 0;
-                               }
-                               samples = i;
-
-                               // for each bit we receive, test if we've detected a valid tag
-
-                               // if we see 17 zeroes followed by 6 ones, we might have a tag
-                               // remember the bits are backwards
-                               if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {
-                                       // if start and end bytes match, we have a tag so break out of the loop
-                                       if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {
-                                               cycles = 0xF0B; //use this as a flag (ugly but whatever)
-                                               break;
-                                       }
-                               }
-                       }
-               }
-       }
-
-       // if flag is set we have a tag
-       if (cycles!=0xF0B) {
-               DbpString("Info: No valid tag detected.");
-       } else {
-         // put 64 bit data into shift1 and shift0
-         shift0 = (shift0>>24) | (shift1 << 8);
-         shift1 = (shift1>>24) | (shift2 << 8);
-
-               // align 16 bit crc into lower half of shift2
-         shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
-
-               // if r/w tag, check ident match
-               if ( shift3&(1<<15) ) {
-                       DbpString("Info: TI tag is rewriteable");
-                       // only 15 bits compare, last bit of ident is not valid
-                       if ( ((shift3>>16)^shift0)&0x7fff ) {
-                               DbpString("Error: Ident mismatch!");
-                       } else {
-                               DbpString("Info: TI tag ident is valid");
-                       }
-               } else {
-                       DbpString("Info: TI tag is readonly");
-               }
-
-               // WARNING the order of the bytes in which we calc crc below needs checking
-               // i'm 99% sure the crc algorithm is correct, but it may need to eat the
-               // bytes in reverse or something
-               // calculate CRC
-               uint32_t crc=0;
-
-               crc = update_crc16(crc, (shift0)&0xff);
-               crc = update_crc16(crc, (shift0>>8)&0xff);
-               crc = update_crc16(crc, (shift0>>16)&0xff);
-               crc = update_crc16(crc, (shift0>>24)&0xff);
-               crc = update_crc16(crc, (shift1)&0xff);
-               crc = update_crc16(crc, (shift1>>8)&0xff);
-               crc = update_crc16(crc, (shift1>>16)&0xff);
-               crc = update_crc16(crc, (shift1>>24)&0xff);
-
-               Dbprintf("Info: Tag data: %x%08x, crc=%x",
-                       (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
-               if (crc != (shift2&0xffff)) {
-                       Dbprintf("Error: CRC mismatch, expected %x", (unsigned int)crc);
-               } else {
-                       DbpString("Info: CRC is good");
-               }
-       }
+    // some hardcoded initial params
+    // when we read a TI tag we sample the zerocross line at 2Mhz
+    // TI tags modulate a 1 as 16 cycles of 123.2Khz
+    // TI tags modulate a 0 as 16 cycles of 134.2Khz
+ #define FSAMPLE 2000000
+ #define FREQLO 123200
+ #define FREQHI 134200
+
+    signed char *dest = (signed char *)BigBuf;
+    int n = sizeof(BigBuf);
+    // 128 bit shift register [shift3:shift2:shift1:shift0]
+    uint32_t shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
+
+    int i, cycles=0, samples=0;
+    // how many sample points fit in 16 cycles of each frequency
+    uint32_t sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
+    // when to tell if we're close enough to one freq or another
+    uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
+
+    // TI tags charge at 134.2Khz
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+
+    // Place FPGA in passthrough mode, in this mode the CROSS_LO line
+    // connects to SSP_DIN and the SSP_DOUT logic level controls
+    // whether we're modulating the antenna (high)
+    // or listening to the antenna (low)
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
+
+    // get TI tag data into the buffer
+    AcquireTiType();
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+
+    for (i=0; i<n-1; i++) {
+        // count cycles by looking for lo to hi zero crossings
+        if ( (dest[i]<0) && (dest[i+1]>0) ) {
+            cycles++;
+            // after 16 cycles, measure the frequency
+            if (cycles>15) {
+                cycles=0;
+                samples=i-samples; // number of samples in these 16 cycles
+
+                // TI bits are coming to us lsb first so shift them
+                // right through our 128 bit right shift register
+                shift0 = (shift0>>1) | (shift1 << 31);
+                shift1 = (shift1>>1) | (shift2 << 31);
+                shift2 = (shift2>>1) | (shift3 << 31);
+                shift3 >>= 1;
+
+                // check if the cycles fall close to the number
+                // expected for either the low or high frequency
+                if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {
+                    // low frequency represents a 1
+                    shift3 |= (1<<31);
+                } else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {
+                    // high frequency represents a 0
+                } else {
+                    // probably detected a gay waveform or noise
+                    // use this as gaydar or discard shift register and start again
+                    shift3 = shift2 = shift1 = shift0 = 0;
+                }
+                samples = i;
+
+                // for each bit we receive, test if we've detected a valid tag
+
+                // if we see 17 zeroes followed by 6 ones, we might have a tag
+                // remember the bits are backwards
+                if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {
+                    // if start and end bytes match, we have a tag so break out of the loop
+                    if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {
+                        cycles = 0xF0B; //use this as a flag (ugly but whatever)
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    // if flag is set we have a tag
+    if (cycles!=0xF0B) {
+        DbpString("Info: No valid tag detected.");
+    } else {
+        // put 64 bit data into shift1 and shift0
+        shift0 = (shift0>>24) | (shift1 << 8);
+        shift1 = (shift1>>24) | (shift2 << 8);
+
+        // align 16 bit crc into lower half of shift2
+        shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+
+        // if r/w tag, check ident match
+               if (shift3 & (1<<15) ) {
+            DbpString("Info: TI tag is rewriteable");
+            // only 15 bits compare, last bit of ident is not valid
+                       if (((shift3 >> 16) ^ shift0) & 0x7fff ) {
+                DbpString("Error: Ident mismatch!");
+            } else {
+                DbpString("Info: TI tag ident is valid");
+            }
+        } else {
+            DbpString("Info: TI tag is readonly");
+        }
+
+        // WARNING the order of the bytes in which we calc crc below needs checking
+        // i'm 99% sure the crc algorithm is correct, but it may need to eat the
+        // bytes in reverse or something
+        // calculate CRC
+        uint32_t crc=0;
+
+        crc = update_crc16(crc, (shift0)&0xff);
+        crc = update_crc16(crc, (shift0>>8)&0xff);
+        crc = update_crc16(crc, (shift0>>16)&0xff);
+        crc = update_crc16(crc, (shift0>>24)&0xff);
+        crc = update_crc16(crc, (shift1)&0xff);
+        crc = update_crc16(crc, (shift1>>8)&0xff);
+        crc = update_crc16(crc, (shift1>>16)&0xff);
+        crc = update_crc16(crc, (shift1>>24)&0xff);
+
+        Dbprintf("Info: Tag data: %x%08x, crc=%x",
+                 (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
+        if (crc != (shift2&0xffff)) {
+            Dbprintf("Error: CRC mismatch, expected %x", (unsigned int)crc);
+        } else {
+            DbpString("Info: CRC is good");
+        }
+    }
 }
 
 void WriteTIbyte(uint8_t b)
 {
-       int i = 0;
-
-       // modulate 8 bits out to the antenna
-       for (i=0; i<8; i++)
-       {
-               if (b&(1<<i)) {
-                       // stop modulating antenna
-                       LOW(GPIO_SSC_DOUT);
-                       SpinDelayUs(1000);
-                       // modulate antenna
-                       HIGH(GPIO_SSC_DOUT);
-                       SpinDelayUs(1000);
-               } else {
-                       // stop modulating antenna
-                       LOW(GPIO_SSC_DOUT);
-                       SpinDelayUs(300);
-                       // modulate antenna
-                       HIGH(GPIO_SSC_DOUT);
-                       SpinDelayUs(1700);
-               }
-       }
+    int i = 0;
+
+    // modulate 8 bits out to the antenna
+    for (i=0; i<8; i++)
+    {
+        if (b&(1<<i)) {
+            // stop modulating antenna
+            LOW(GPIO_SSC_DOUT);
+            SpinDelayUs(1000);
+            // modulate antenna
+            HIGH(GPIO_SSC_DOUT);
+            SpinDelayUs(1000);
+        } else {
+            // stop modulating antenna
+            LOW(GPIO_SSC_DOUT);
+            SpinDelayUs(300);
+            // modulate antenna
+            HIGH(GPIO_SSC_DOUT);
+            SpinDelayUs(1700);
+        }
+    }
 }
 
 void AcquireTiType(void)
 {
-       int i, j, n;
-       // tag transmission is <20ms, sampling at 2M gives us 40K samples max
-       // each sample is 1 bit stuffed into a uint32_t so we need 1250 uint32_t
      #define TIBUFLEN 1250
-
-       // clear buffer
-       memset(BigBuf,0,sizeof(BigBuf));
-
-       // Set up the synchronous serial port
-       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;
-       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN;
-
-       // steal this pin from the SSP and use it to control the modulation
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-
-       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_SWRST;
-       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_RXEN | AT91C_SSC_TXEN;
-
-       // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long
-       // 48/2 = 24 MHz clock must be divided by 12
-       AT91C_BASE_SSC->SSC_CMR = 12;
-
-       AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(0);
-       AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(32) | AT91C_SSC_MSBF;
-       AT91C_BASE_SSC->SSC_TCMR = 0;
-       AT91C_BASE_SSC->SSC_TFMR = 0;
-
-       LED_D_ON();
-
-       // modulate antenna
-       HIGH(GPIO_SSC_DOUT);
-
-       // Charge TI tag for 50ms.
-       SpinDelay(50);
-
-       // stop modulating antenna and listen
-       LOW(GPIO_SSC_DOUT);
-
-       LED_D_OFF();
-
-       i = 0;
-       for(;;) {
-               if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
-                       BigBuf[i] = AT91C_BASE_SSC->SSC_RHR;    // store 32 bit values in buffer
-                       i++; if(i >= TIBUFLEN) break;
-               }
-               WDT_HIT();
-       }
-
-       // return stolen pin to SSP
-       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
-       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
-
-       char *dest = (char *)BigBuf;
-       n = TIBUFLEN*32;
-       // unpack buffer
-       for (i=TIBUFLEN-1; i>=0; i--) {
-               for (j=0; j<32; j++) {
-                       if(BigBuf[i] & (1 << j)) {
-                               dest[--n] = 1;
-                       } else {
-                               dest[--n] = -1;
-                       }
-               }
-       }
+    int i, j, n;
+    // tag transmission is <20ms, sampling at 2M gives us 40K samples max
+    // each sample is 1 bit stuffed into a uint32_t so we need 1250 uint32_t
+ #define TIBUFLEN 1250
+
+    // clear buffer
+    memset(BigBuf,0,sizeof(BigBuf));
+
+    // Set up the synchronous serial port
+    AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;
+    AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN;
+
+    // steal this pin from the SSP and use it to control the modulation
+    AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+    AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+    AT91C_BASE_SSC->SSC_CR = AT91C_SSC_SWRST;
+    AT91C_BASE_SSC->SSC_CR = AT91C_SSC_RXEN | AT91C_SSC_TXEN;
+
+    // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long
+    // 48/2 = 24 MHz clock must be divided by 12
+    AT91C_BASE_SSC->SSC_CMR = 12;
+
+    AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(0);
+    AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(32) | AT91C_SSC_MSBF;
+    AT91C_BASE_SSC->SSC_TCMR = 0;
+    AT91C_BASE_SSC->SSC_TFMR = 0;
+
+    LED_D_ON();
+
+    // modulate antenna
+    HIGH(GPIO_SSC_DOUT);
+
+    // Charge TI tag for 50ms.
+    SpinDelay(50);
+
+    // stop modulating antenna and listen
+    LOW(GPIO_SSC_DOUT);
+
+    LED_D_OFF();
+
+    i = 0;
+    for(;;) {
+        if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            BigBuf[i] = AT91C_BASE_SSC->SSC_RHR;       // store 32 bit values in buffer
+            i++; if(i >= TIBUFLEN) break;
+        }
+        WDT_HIT();
+    }
+
+    // return stolen pin to SSP
+    AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
+    AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
+
+    char *dest = (char *)BigBuf;
+    n = TIBUFLEN*32;
+    // unpack buffer
+    for (i=TIBUFLEN-1; i>=0; i--) {
+        for (j=0; j<32; j++) {
+            if(BigBuf[i] & (1 << j)) {
+                dest[--n] = 1;
+            } else {
+                dest[--n] = -1;
+            }
+        }
+    }
 }
 
 // arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc
@@ -363,617 +397,439 @@ void AcquireTiType(void)
 // if not provided a valid crc will be computed from the data and written.
 void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
 {
-       if(crc == 0) {
-               crc = update_crc16(crc, (idlo)&0xff);
-               crc = update_crc16(crc, (idlo>>8)&0xff);
-               crc = update_crc16(crc, (idlo>>16)&0xff);
-               crc = update_crc16(crc, (idlo>>24)&0xff);
-               crc = update_crc16(crc, (idhi)&0xff);
-               crc = update_crc16(crc, (idhi>>8)&0xff);
-               crc = update_crc16(crc, (idhi>>16)&0xff);
-               crc = update_crc16(crc, (idhi>>24)&0xff);
-       }
-       Dbprintf("Writing to tag: %x%08x, crc=%x",
-               (unsigned int) idhi, (unsigned int) idlo, crc);
-
-       // TI tags charge at 134.2Khz
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       // Place FPGA in passthrough mode, in this mode the CROSS_LO line
-       // connects to SSP_DIN and the SSP_DOUT logic level controls
-       // whether we're modulating the antenna (high)
-       // or listening to the antenna (low)
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
-       LED_A_ON();
-
-       // steal this pin from the SSP and use it to control the modulation
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-
-       // writing algorithm:
-       // a high bit consists of a field off for 1ms and field on for 1ms
-       // a low bit consists of a field off for 0.3ms and field on for 1.7ms
-       // initiate a charge time of 50ms (field on) then immediately start writing bits
-       // start by writing 0xBB (keyword) and 0xEB (password)
-       // then write 80 bits of data (or 64 bit data + 16 bit crc if you prefer)
-       // finally end with 0x0300 (write frame)
-       // all data is sent lsb firts
-       // finish with 15ms programming time
-
-       // modulate antenna
-       HIGH(GPIO_SSC_DOUT);
-       SpinDelay(50);  // charge time
-
-       WriteTIbyte(0xbb); // keyword
-       WriteTIbyte(0xeb); // password
-       WriteTIbyte( (idlo    )&0xff );
-       WriteTIbyte( (idlo>>8 )&0xff );
-       WriteTIbyte( (idlo>>16)&0xff );
-       WriteTIbyte( (idlo>>24)&0xff );
-       WriteTIbyte( (idhi    )&0xff );
-       WriteTIbyte( (idhi>>8 )&0xff );
-       WriteTIbyte( (idhi>>16)&0xff );
-       WriteTIbyte( (idhi>>24)&0xff ); // data hi to lo
-       WriteTIbyte( (crc     )&0xff ); // crc lo
-       WriteTIbyte( (crc>>8  )&0xff ); // crc hi
-       WriteTIbyte(0x00); // write frame lo
-       WriteTIbyte(0x03); // write frame hi
-       HIGH(GPIO_SSC_DOUT);
-       SpinDelay(50);  // programming time
-
-       LED_A_OFF();
-
-       // get TI tag data into the buffer
-       AcquireTiType();
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       DbpString("Now use tiread to check");
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    if(crc == 0) {
+        crc = update_crc16(crc, (idlo)&0xff);
+        crc = update_crc16(crc, (idlo>>8)&0xff);
+        crc = update_crc16(crc, (idlo>>16)&0xff);
+        crc = update_crc16(crc, (idlo>>24)&0xff);
+        crc = update_crc16(crc, (idhi)&0xff);
+        crc = update_crc16(crc, (idhi>>8)&0xff);
+        crc = update_crc16(crc, (idhi>>16)&0xff);
+        crc = update_crc16(crc, (idhi>>24)&0xff);
+    }
+    Dbprintf("Writing to tag: %x%08x, crc=%x",
+             (unsigned int) idhi, (unsigned int) idlo, crc);
+
+    // TI tags charge at 134.2Khz
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+    // Place FPGA in passthrough mode, in this mode the CROSS_LO line
+    // connects to SSP_DIN and the SSP_DOUT logic level controls
+    // whether we're modulating the antenna (high)
+    // or listening to the antenna (low)
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
+    LED_A_ON();
+
+    // steal this pin from the SSP and use it to control the modulation
+    AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+    AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+    // writing algorithm:
+    // a high bit consists of a field off for 1ms and field on for 1ms
+    // a low bit consists of a field off for 0.3ms and field on for 1.7ms
+    // initiate a charge time of 50ms (field on) then immediately start writing bits
+    // start by writing 0xBB (keyword) and 0xEB (password)
+    // then write 80 bits of data (or 64 bit data + 16 bit crc if you prefer)
+    // finally end with 0x0300 (write frame)
+    // all data is sent lsb firts
+    // finish with 15ms programming time
+
+    // modulate antenna
+    HIGH(GPIO_SSC_DOUT);
+    SpinDelay(50);     // charge time
+
+    WriteTIbyte(0xbb); // keyword
+    WriteTIbyte(0xeb); // password
+    WriteTIbyte( (idlo    )&0xff );
+    WriteTIbyte( (idlo>>8 )&0xff );
+    WriteTIbyte( (idlo>>16)&0xff );
+    WriteTIbyte( (idlo>>24)&0xff );
+    WriteTIbyte( (idhi    )&0xff );
+    WriteTIbyte( (idhi>>8 )&0xff );
+    WriteTIbyte( (idhi>>16)&0xff );
+    WriteTIbyte( (idhi>>24)&0xff ); // data hi to lo
+    WriteTIbyte( (crc     )&0xff ); // crc lo
+    WriteTIbyte( (crc>>8  )&0xff ); // crc hi
+    WriteTIbyte(0x00); // write frame lo
+    WriteTIbyte(0x03); // write frame hi
+    HIGH(GPIO_SSC_DOUT);
+    SpinDelay(50);     // programming time
+
+    LED_A_OFF();
+
+    // get TI tag data into the buffer
+    AcquireTiType();
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    DbpString("Now use tiread to check");
 }
 
 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 {
-       int i;
-       uint8_t *tab = (uint8_t *)BigBuf;
+    int i;
+    uint8_t *tab = (uint8_t *)BigBuf;
 
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
 
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
+    AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
 
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-       AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
+    AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+    AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
 
 #define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
 #define OPEN_COIL()            HIGH(GPIO_SSC_DOUT)
 
-       i = 0;
-       for(;;) {
-               while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
-                               return;
-                       }
-                       WDT_HIT();
-               }
-
-               if (ledcontrol)
-                       LED_D_ON();
-
-               if(tab[i])
-                       OPEN_COIL();
-               else
-                       SHORT_COIL();
-
-               if (ledcontrol)
-                       LED_D_OFF();
-
-               while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
-                               return;
-                       }
-                       WDT_HIT();
-               }
-
-               i++;
-               if(i == period) {
-                       i = 0;
-                       if (gap) {
-                               SHORT_COIL();
-                               SpinDelayUs(gap);
-                       }
-               }
-       }
+    i = 0;
+    for(;;) {
+        while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
+            if(BUTTON_PRESS()) {
+                DbpString("Stopped");
+                return;
+            }
+            WDT_HIT();
+        }
+
+        if (ledcontrol)
+            LED_D_ON();
+
+        if(tab[i])
+            OPEN_COIL();
+        else
+            SHORT_COIL();
+
+        if (ledcontrol)
+            LED_D_OFF();
+
+        while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
+            if(BUTTON_PRESS()) {
+                DbpString("Stopped");
+                return;
+            }
+            WDT_HIT();
+        }
+
+        i++;
+        if(i == period) {
+            i = 0;
+            if (gap) {
+                SHORT_COIL();
+                SpinDelayUs(gap);
+            }
+        }
+    }
 }
 
-/* Provides a framework for bidirectional LF tag communication
- * Encoding is currently Hitag2, but the general idea can probably
- * be transferred to other encodings.
- *
- * The new FPGA code will, for the LF simulator mode, give on SSC_FRAME
- * (PA15) a thresholded version of the signal from the ADC. Setting the
- * ADC path to the low frequency peak detection signal, will enable a
- * somewhat reasonable receiver for modulation on the carrier signal
- * that is generated by the reader. The signal is low when the reader
- * field is switched off, and high when the reader field is active. Due
- * to the way that the signal looks like, mostly only the rising edge is
- * useful, your mileage may vary.
- *
- * Neat perk: PA15 can not only be used as a bit-banging GPIO, but is also
- * TIOA1, which can be used as the capture input for timer 1. This should
- * make it possible to measure the exact edge-to-edge time, without processor
- * intervention.
- *
- * Arguments: divisor is the divisor to be sent to the FPGA (e.g. 95 for 125kHz)
- * t0 is the carrier frequency cycle duration in terms of MCK (384 for 125kHz)
- *
- * The following defines are in carrier periods:
- */
-#define HITAG_T_0_MIN 15 /* T[0] should be 18..22 */
-#define HITAG_T_1_MIN 24 /* T[1] should be 26..30 */
-#define HITAG_T_EOF   40 /* T_EOF should be > 36 */
-#define HITAG_T_WRESP 208 /* T_wresp should be 204..212 */
-
-static void hitag_handle_frame(int t0, int frame_len, char *frame);
-//#define DEBUG_RA_VALUES 1
 #define DEBUG_FRAME_CONTENTS 1
 void SimulateTagLowFrequencyBidir(int divisor, int t0)
 {
-#if DEBUG_RA_VALUES || DEBUG_FRAME_CONTENTS
-       int i = 0;
-#endif
-       char frame[10];
-       int frame_pos=0;
-
-       DbpString("Starting Hitag2 emulator, press button to end");
-       hitag2_init();
-
-       /* Set up simulator mode, frequency divisor which will drive the FPGA
-        * and analog mux selection.
-        */
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-       RELAY_OFF();
-
-       /* Set up Timer 1:
-        * Capture mode, timer source MCK/2 (TIMER_CLOCK1), TIOA is external trigger,
-        * external trigger rising edge, load RA on rising edge of TIOA, load RB on rising
-        * edge of TIOA. Assign PA15 to TIOA1 (peripheral B)
-        */
-
-       AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
-       AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME;
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
-       AT91C_BASE_TC1->TC_CMR =        AT91C_TC_CLKS_TIMER_DIV1_CLOCK |
-                                                               AT91C_TC_ETRGEDG_RISING |
-                                                               AT91C_TC_ABETRG |
-                                                               AT91C_TC_LDRA_RISING |
-                                                               AT91C_TC_LDRB_RISING;
-       AT91C_BASE_TC1->TC_CCR =        AT91C_TC_CLKEN |
-                                                               AT91C_TC_SWTRG;
-
-       /* calculate the new value for the carrier period in terms of TC1 values */
-       t0 = t0/2;
-
-       int overflow = 0;
-       while(!BUTTON_PRESS()) {
-               WDT_HIT();
-               if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) {
-                       int ra = AT91C_BASE_TC1->TC_RA;
-                       if((ra > t0*HITAG_T_EOF) | overflow) ra = t0*HITAG_T_EOF+1;
-#if DEBUG_RA_VALUES
-                       if(ra > 255 || overflow) ra = 255;
-                       ((char*)BigBuf)[i] = ra;
-                       i = (i+1) % 8000;
-#endif
-
-                       if(overflow || (ra > t0*HITAG_T_EOF) || (ra < t0*HITAG_T_0_MIN)) {
-                               /* Ignore */
-                       } else if(ra >= t0*HITAG_T_1_MIN ) {
-                               /* '1' bit */
-                               if(frame_pos < 8*sizeof(frame)) {
-                                       frame[frame_pos / 8] |= 1<<( 7-(frame_pos%8) );
-                                       frame_pos++;
-                               }
-                       } else if(ra >= t0*HITAG_T_0_MIN) {
-                               /* '0' bit */
-                               if(frame_pos < 8*sizeof(frame)) {
-                                       frame[frame_pos / 8] |= 0<<( 7-(frame_pos%8) );
-                                       frame_pos++;
-                               }
-                       }
-
-                       overflow = 0;
-                       LED_D_ON();
-               } else {
-                       if(AT91C_BASE_TC1->TC_CV > t0*HITAG_T_EOF) {
-                               /* Minor nuisance: In Capture mode, the timer can not be
-                                * stopped by a Compare C. There's no way to stop the clock
-                                * in software, so we'll just have to note the fact that an
-                                * overflow happened and the next loaded timer value might
-                                * have wrapped. Also, this marks the end of frame, and the
-                                * still running counter can be used to determine the correct
-                                * time for the start of the reply.
-                                */
-                               overflow = 1;
-
-                               if(frame_pos > 0) {
-                                       /* Have a frame, do something with it */
-#if DEBUG_FRAME_CONTENTS
-                                       ((char*)BigBuf)[i++] = frame_pos;
-                                       memcpy( ((char*)BigBuf)+i, frame, 7);
-                                       i+=7;
-                                       i = i % sizeof(BigBuf);
-#endif
-                                       hitag_handle_frame(t0, frame_pos, frame);
-                                       memset(frame, 0, sizeof(frame));
-                               }
-                               frame_pos = 0;
-
-                       }
-                       LED_D_OFF();
-               }
-       }
-       DbpString("All done");
-}
-
-static void hitag_send_bit(int t0, int bit) {
-       if(bit == 1) {
-               /* Manchester: Loaded, then unloaded */
-               LED_A_ON();
-               SHORT_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*15);
-               OPEN_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*31);
-               LED_A_OFF();
-       } else if(bit == 0) {
-               /* Manchester: Unloaded, then loaded */
-               LED_B_ON();
-               OPEN_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*15);
-               SHORT_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*31);
-               LED_B_OFF();
-       }
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset clock for the next bit */
-
-}
-static void hitag_send_frame(int t0, int frame_len, const char const * frame, int fdt)
-{
-       OPEN_COIL();
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-
-       /* Wait for HITAG_T_WRESP carrier periods after the last reader bit,
-        * not that since the clock counts since the rising edge, but T_wresp is
-        * with respect to the falling edge, we need to wait actually (T_wresp - T_g)
-        * periods. The gap time T_g varies (4..10).
-        */
-       while(AT91C_BASE_TC1->TC_CV < t0*(fdt-8));
-
-       int saved_cmr = AT91C_BASE_TC1->TC_CMR;
-       AT91C_BASE_TC1->TC_CMR &= ~AT91C_TC_ETRGEDG; /* Disable external trigger for the clock */
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset the clock and use it for response timing */
-
-       int i;
-       for(i=0; i<5; i++)
-               hitag_send_bit(t0, 1); /* Start of frame */
-
-       for(i=0; i<frame_len; i++) {
-               hitag_send_bit(t0, !!(frame[i/ 8] & (1<<( 7-(i%8) ))) );
-       }
-
-       OPEN_COIL();
-       AT91C_BASE_TC1->TC_CMR = saved_cmr;
-}
-
-/* Callback structure to cleanly separate tag emulation code from the radio layer. */
-static int hitag_cb(const char* response_data, const int response_length, const int fdt, void *cb_cookie)
-{
-       hitag_send_frame(*(int*)cb_cookie, response_length, response_data, fdt);
-       return 0;
-}
-/* Frame length in bits, frame contents in MSBit first format */
-static void hitag_handle_frame(int t0, int frame_len, char *frame)
-{
-       hitag2_handle_command(frame, frame_len, hitag_cb, &t0);
 }
 
 // compose fc/8 fc/10 waveform
 static void fc(int c, int *n) {
-       uint8_t *dest = (uint8_t *)BigBuf;
-       int idx;
-
-       // for when we want an fc8 pattern every 4 logical bits
-       if(c==0) {
-               dest[((*n)++)]=1;
-               dest[((*n)++)]=1;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
-       }
-       //      an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples
-       if(c==8) {
-               for (idx=0; idx<6; idx++) {
-                       dest[((*n)++)]=1;
-                       dest[((*n)++)]=1;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-               }
-       }
-
-       //      an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
-       if(c==10) {
-               for (idx=0; idx<5; idx++) {
-                       dest[((*n)++)]=1;
-                       dest[((*n)++)]=1;
-                       dest[((*n)++)]=1;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-               }
-       }
+    uint8_t *dest = (uint8_t *)BigBuf;
+    int idx;
+
+    // for when we want an fc8 pattern every 4 logical bits
+    if(c==0) {
+        dest[((*n)++)]=1;
+        dest[((*n)++)]=1;
+        dest[((*n)++)]=0;
+        dest[((*n)++)]=0;
+        dest[((*n)++)]=0;
+        dest[((*n)++)]=0;
+        dest[((*n)++)]=0;
+        dest[((*n)++)]=0;
+    }
+    // an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples
+    if(c==8) {
+        for (idx=0; idx<6; idx++) {
+            dest[((*n)++)]=1;
+            dest[((*n)++)]=1;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+        }
+    }
+
+    // an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
+    if(c==10) {
+        for (idx=0; idx<5; idx++) {
+            dest[((*n)++)]=1;
+            dest[((*n)++)]=1;
+            dest[((*n)++)]=1;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+            dest[((*n)++)]=0;
+        }
+    }
 }
 
 // prepare a waveform pattern in the buffer based on the ID given then
 // simulate a HID tag until the button is pressed
 void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
 {
-       int n=0, i=0;
-       /*
-        HID tag bitstream format
-        The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
-        A 1 bit is represented as 6 fc8 and 5 fc10 patterns
-        A 0 bit is represented as 5 fc10 and 6 fc8 patterns
-        A fc8 is inserted before every 4 bits
-        A special start of frame pattern is used consisting a0b0 where a and b are neither 0
-        nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
-       */
-
-       if (hi>0xFFF) {
-               DbpString("Tags can only have 44 bits.");
-               return;
-       }
-       fc(0,&n);
-       // special start of frame marker containing invalid bit sequences
-       fc(8,  &n);     fc(8,  &n);     // invalid
-       fc(8,  &n);     fc(10, &n); // logical 0
-       fc(10, &n);     fc(10, &n); // invalid
-       fc(8,  &n);     fc(10, &n); // logical 0
-
-       WDT_HIT();
-       // manchester encode bits 43 to 32
-       for (i=11; i>=0; i--) {
-               if ((i%4)==3) fc(0,&n);
-               if ((hi>>i)&1) {
-                       fc(10, &n);     fc(8,  &n);             // low-high transition
-               } else {
-                       fc(8,  &n);     fc(10, &n);             // high-low transition
-               }
-       }
-
-       WDT_HIT();
-       // manchester encode bits 31 to 0
-       for (i=31; i>=0; i--) {
-               if ((i%4)==3) fc(0,&n);
-               if ((lo>>i)&1) {
-                       fc(10, &n);     fc(8,  &n);             // low-high transition
-               } else {
-                       fc(8,  &n);     fc(10, &n);             // high-low transition
-               }
-       }
-
-       if (ledcontrol)
-               LED_A_ON();
-       SimulateTagLowFrequency(n, 0, ledcontrol);
-
-       if (ledcontrol)
-               LED_A_OFF();
+    int n=0, i=0;
+    /*
+     HID tag bitstream format
+     The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
+     A 1 bit is represented as 6 fc8 and 5 fc10 patterns
+     A 0 bit is represented as 5 fc10 and 6 fc8 patterns
+     A fc8 is inserted before every 4 bits
+     A special start of frame pattern is used consisting a0b0 where a and b are neither 0
+     nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
+    */
+
+    if (hi>0xFFF) {
+        DbpString("Tags can only have 44 bits.");
+        return;
+    }
+    fc(0,&n);
+    // special start of frame marker containing invalid bit sequences
+    fc(8,  &n);        fc(8,  &n);     // invalid
+    fc(8,  &n);        fc(10, &n); // logical 0
+    fc(10, &n);        fc(10, &n); // invalid
+    fc(8,  &n);        fc(10, &n); // logical 0
+
+    WDT_HIT();
+    // manchester encode bits 43 to 32
+    for (i=11; i>=0; i--) {
+        if ((i%4)==3) fc(0,&n);
+        if ((hi>>i)&1) {
+            fc(10, &n);        fc(8,  &n);             // low-high transition
+        } else {
+            fc(8,  &n);        fc(10, &n);             // high-low transition
+        }
+    }
+
+    WDT_HIT();
+    // manchester encode bits 31 to 0
+    for (i=31; i>=0; i--) {
+        if ((i%4)==3) fc(0,&n);
+        if ((lo>>i)&1) {
+            fc(10, &n);        fc(8,  &n);             // low-high transition
+        } else {
+            fc(8,  &n);        fc(10, &n);             // high-low transition
+        }
+    }
+
+    if (ledcontrol)
+        LED_A_ON();
+    SimulateTagLowFrequency(n, 0, ledcontrol);
+
+    if (ledcontrol)
+        LED_A_OFF();
 }
 
-
-// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
 void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
 {
-       uint8_t *dest = (uint8_t *)BigBuf;
-       int m=0, n=0, i=0, idx=0, found=0, lastval=0;
-       uint32_t hi=0, lo=0;
-
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
-
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
-
-       for(;;) {
-               WDT_HIT();
-               if (ledcontrol)
-                       LED_A_ON();
-               if(BUTTON_PRESS()) {
-                       DbpString("Stopped");
-                       if (ledcontrol)
-                               LED_A_OFF();
-                       return;
-               }
-
-               i = 0;
-               m = sizeof(BigBuf);
-               memset(dest,128,m);
-               for(;;) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = 0x43;
-                               if (ledcontrol)
-                                       LED_D_ON();
-                       }
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                               dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                               // we don't care about actual value, only if it's more or less than a
-                               // threshold essentially we capture zero crossings for later analysis
-                               if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
-                               i++;
-                               if (ledcontrol)
-                                       LED_D_OFF();
-                               if(i >= m) {
-                                       break;
-                               }
-                       }
-               }
-
-               // FSK demodulator
-
-               // sync to first lo-hi transition
-               for( idx=1; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx])
-                               lastval=idx;
-                               break;
-               }
-               WDT_HIT();
-
-               // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
-               // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
-               // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
-               for( i=0; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx]) {
-                               dest[i]=idx-lastval;
-                               if (dest[i] <= 8) {
-                                               dest[i]=1;
-                               } else {
-                                               dest[i]=0;
-                               }
-
-                               lastval=idx;
-                               i++;
-                       }
-               }
-               m=i;
-               WDT_HIT();
-
-               // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
-               lastval=dest[0];
-               idx=0;
-               i=0;
-               n=0;
-               for( idx=0; idx<m; idx++) {
-                       if (dest[idx]==lastval) {
-                               n++;
-                       } else {
-                               // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
-                               // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
-                               // swallowed up by rounding
-                               // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
-                               // special start of frame markers use invalid manchester states (no transitions) by using sequences
-                               // like 111000
-                               if (dest[idx-1]) {
-                                       n=(n+1)/6;                      // fc/8 in sets of 6
-                               } else {
-                                       n=(n+1)/5;                      // fc/10 in sets of 5
-                               }
-                               switch (n) {                    // stuff appropriate bits in buffer
-                                       case 0:
-                                       case 1: // one bit
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 2: // two bits
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 3: // 3 bit start of frame markers
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       // When a logic 0 is immediately followed by the start of the next transmisson
-                                       // (special pattern) a pattern of 4 bit duration lengths is created.
-                                       case 4:
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       default:        // this shouldn't happen, don't stuff any bits
-                                               break;
-                               }
-                               n=0;
-                               lastval=dest[idx];
-                       }
-               }
-               m=i;
-               WDT_HIT();
-
-               // final loop, go over previously decoded manchester data and decode into usable tag ID
-               // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-               for( idx=0; idx<m-6; idx++) {
-                       // search for a start of frame marker
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-                               if (found && (hi|lo)) {
-                                       Dbprintf("TAG ID: %x%08x (%d)",
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
-                                       }
-                                       hi=0;
-                                       lo=0;
-                                       found=0;
-                               }
-                       }
-                       if (found) {
-                               if (dest[idx] && (!dest[idx+1]) ) {
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|0;
-                               } else if ( (!dest[idx]) && dest[idx+1]) {
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|1;
-                               } else {
-                                       found=0;
-                                       hi=0;
-                                       lo=0;
-                               }
-                               idx++;
-                       }
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-                               if (found && (hi|lo)) {
-                                       Dbprintf("TAG ID: %x%08x (%d)",
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
-                                       }
-                                       hi=0;
-                                       lo=0;
-                                       found=0;
-                               }
-                       }
-               }
-               WDT_HIT();
-       }
+    uint8_t *dest = (uint8_t *)BigBuf;
+
+    size_t size=0; //, found=0;
+    uint32_t hi2=0, hi=0, lo=0;
+
+    // Configure to go in 125Khz listen mode
+    LFSetupFPGAForADC(95, true);
+
+    while(!BUTTON_PRESS()) {
+
+        WDT_HIT();
+        if (ledcontrol) LED_A_ON();
+
+        DoAcquisition125k_internal(-1,true);
+        // FSK demodulator
+               size = HIDdemodFSK(dest, sizeof(BigBuf), &hi2, &hi, &lo);
+
+        WDT_HIT();
+
+               if (size>0 && lo>0){
+            // final loop, go over previously decoded manchester data and decode into usable tag ID
+            // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
+            if (hi2 != 0){ //extra large HID tags
+                Dbprintf("TAG ID: %x%08x%08x (%d)",
+                         (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+            }else {  //standard HID tags <38 bits
+                //Dbprintf("TAG ID: %x%08x (%d)",(unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF); //old print cmd
+                uint8_t bitlen = 0;
+                uint32_t fc = 0;
+                uint32_t cardnum = 0;
+                               if (((hi>>5)&1) == 1){//if bit 38 is set then < 37 bit format is used
+                    uint32_t lo2=0;
+                    lo2=(((hi & 31) << 12) | (lo>>20)); //get bits 21-37 to check for format len bit
+                    uint8_t idx3 = 1;
+                                       while(lo2 > 1){ //find last bit set to 1 (format len bit)
+                                               lo2=lo2 >> 1;
+                        idx3++;
+                    }
+                                       bitlen = idx3+19;
+                    fc =0;
+                    cardnum=0;
+                                       if(bitlen == 26){
+                        cardnum = (lo>>1)&0xFFFF;
+                        fc = (lo>>17)&0xFF;
+                    }
+                                       if(bitlen == 37){
+                        cardnum = (lo>>1)&0x7FFFF;
+                        fc = ((hi&0xF)<<12)|(lo>>20);
+                    }
+                                       if(bitlen == 34){
+                        cardnum = (lo>>1)&0xFFFF;
+                        fc= ((hi&1)<<15)|(lo>>17);
+                    }
+                                       if(bitlen == 35){
+                        cardnum = (lo>>1)&0xFFFFF;
+                        fc = ((hi&1)<<11)|(lo>>21);
+                    }
+                }
+                else { //if bit 38 is not set then 37 bit format is used
+                    bitlen= 37;
+                    fc =0;
+                    cardnum=0;
+                    if(bitlen==37){
+                        cardnum = (lo>>1)&0x7FFFF;
+                        fc = ((hi&0xF)<<12)|(lo>>20);
+                    }
+                }
+                //Dbprintf("TAG ID: %x%08x (%d)",
+                // (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                Dbprintf("TAG ID: %x%08x (%d) - Format Len: %dbit - FC: %d - Card: %d",
+                         (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF,
+                         (unsigned int) bitlen, (unsigned int) fc, (unsigned int) cardnum);
+            }
+            if (findone){
+                if (ledcontrol)        LED_A_OFF();
+                return;
+            }
+            // reset
+            hi2 = hi = lo = 0;
+        }
+        WDT_HIT();
+    }
+    DbpString("Stopped");
+    if (ledcontrol) LED_A_OFF();
+}
+
+void CmdEM410xdemod(int findone, int *high, int *low, int ledcontrol)
+{
+    uint8_t *dest = (uint8_t *)BigBuf;
+
+       size_t size=0;
+    int clk=0, invert=0, errCnt=0;
+    uint64_t lo=0;
+    // Configure to go in 125Khz listen mode
+    LFSetupFPGAForADC(95, true);
+
+    while(!BUTTON_PRESS()) {
+
+        WDT_HIT();
+        if (ledcontrol) LED_A_ON();
+
+        DoAcquisition125k_internal(-1,true);
+        size  = sizeof(BigBuf);
+        //Dbprintf("DEBUG: Buffer got");
+               //askdemod and manchester decode
+               errCnt = askmandemod(dest, &size, &clk, &invert);
+        //Dbprintf("DEBUG: ASK Got");
+        WDT_HIT();
+
+        if (errCnt>=0){
+                       lo = Em410xDecode(dest,size);
+            //Dbprintf("DEBUG: EM GOT");
+            if (lo>0){
+                               Dbprintf("EM TAG ID: %02x%08x - (%05d_%03d_%08d)",
+                                   (uint32_t)(lo>>32),
+                                   (uint32_t)lo,
+                                   (uint32_t)(lo&0xFFFF),
+                                   (uint32_t)((lo>>16LL) & 0xFF),
+                                   (uint32_t)(lo & 0xFFFFFF));
+            }
+            if (findone){
+                if (ledcontrol)        LED_A_OFF();
+                return;
+            }
+        } else{
+            //Dbprintf("DEBUG: No Tag");
+        }
+        WDT_HIT();
+        lo = 0;
+        clk=0;
+        invert=0;
+        errCnt=0;
+        size=0;
+    }
+    DbpString("Stopped");
+    if (ledcontrol) LED_A_OFF();
+}
+
+void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+    uint8_t *dest = (uint8_t *)BigBuf;
+    int idx=0;
+    uint32_t code=0, code2=0;
+    uint8_t version=0;
+    uint8_t facilitycode=0;
+    uint16_t number=0;
+    // Configure to go in 125Khz listen mode
+    LFSetupFPGAForADC(95, true);
+
+    while(!BUTTON_PRESS()) {
+        WDT_HIT();
+        if (ledcontrol) LED_A_ON();
+        DoAcquisition125k_internal(-1,true);
+        //fskdemod and get start index
+        WDT_HIT();
+        idx = IOdemodFSK(dest,sizeof(BigBuf));
+        if (idx>0){
+            //valid tag found
+
+            //Index map
+            //0           10          20          30          40          50          60
+            //|           |           |           |           |           |           |
+            //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+            //-----------------------------------------------------------------------------
+            //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+            //
+            //XSF(version)facility:codeone+codetwo
+            //Handle the data
+            if(findone){ //only print binary if we are doing one
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx],   dest[idx+1],   dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7],dest[idx+8]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15],dest[idx+16],dest[idx+17]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23],dest[idx+24],dest[idx+25],dest[idx+26]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+27],dest[idx+28],dest[idx+29],dest[idx+30],dest[idx+31],dest[idx+32],dest[idx+33],dest[idx+34],dest[idx+35]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+36],dest[idx+37],dest[idx+38],dest[idx+39],dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+45],dest[idx+46],dest[idx+47],dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53]);
+                Dbprintf("%d%d%d%d%d%d%d%d %d%d",dest[idx+54],dest[idx+55],dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
+            }
+            code = bytebits_to_byte(dest+idx,32);
+            code2 = bytebits_to_byte(dest+idx+32,32);
+            version = bytebits_to_byte(dest+idx+27,8); //14,4
+            facilitycode = bytebits_to_byte(dest+idx+18,8) ;
+            number = (bytebits_to_byte(dest+idx+36,8)<<8)|(bytebits_to_byte(dest+idx+45,8)); //36,9
+
+            Dbprintf("XSF(%02d)%02x:%05d (%08x%08x)",version,facilitycode,number,code,code2);
+            // if we're only looking for one tag
+            if (findone){
+                if (ledcontrol)        LED_A_OFF();
+                //LED_A_OFF();
+                return;
+            }
+            code=code2=0;
+            version=facilitycode=0;
+            number=0;
+            idx=0;
+        }
+        WDT_HIT();
+    }
+    DbpString("Stopped");
+    if (ledcontrol) LED_A_OFF();
 }
 
 /*------------------------------
@@ -1043,104 +899,321 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
 // Write one bit to card
 void T55xxWriteBit(int bit)
 {
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-       if (bit == 0)
-               SpinDelayUs(WRITE_0);
-       else
-               SpinDelayUs(WRITE_1);
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelayUs(WRITE_GAP);
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+    if (bit == 0)
+        SpinDelayUs(WRITE_0);
+    else
+        SpinDelayUs(WRITE_1);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    SpinDelayUs(WRITE_GAP);
 }
 
 // Write one card block in page 0, no lock
-void T55xxWriteBlock(int Data, int Block)
+void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t PwdMode)
+{
+    //unsigned int i;  //enio adjustment 12/10/14
+    uint32_t i;
+
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Give it a bit of time for the resonant antenna to settle.
+    // And for the tag to fully power up
+    SpinDelay(150);
+
+    // Now start writting
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    SpinDelayUs(START_GAP);
+
+    // Opcode
+    T55xxWriteBit(1);
+    T55xxWriteBit(0); //Page 0
+    if (PwdMode == 1){
+        // Pwd
+        for (i = 0x80000000; i != 0; i >>= 1)
+            T55xxWriteBit(Pwd & i);
+    }
+    // Lock bit
+    T55xxWriteBit(0);
+
+    // Data
+    for (i = 0x80000000; i != 0; i >>= 1)
+        T55xxWriteBit(Data & i);
+
+    // Block
+    for (i = 0x04; i != 0; i >>= 1)
+        T55xxWriteBit(Block & i);
+
+    // Now perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
+    // so wait a little more)
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+    SpinDelay(20);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+}
+
+// Read one card block in page 0
+void T55xxReadBlock(uint32_t Block, uint32_t Pwd, uint8_t PwdMode)
 {
-       unsigned int i;
-
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // Give it a bit of time for the resonant antenna to settle.
-       // And for the tag to fully power up
-       SpinDelay(150);
-
-       // Now start writting
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelayUs(START_GAP);
-
-       // Opcode
-       T55xxWriteBit(1);
-       T55xxWriteBit(0); //Page 0
-       // Lock bit
-       T55xxWriteBit(0);
-
-       // Data
-       for (i = 0x80000000; i != 0; i >>= 1)
-               T55xxWriteBit(Data & i);
-
-       // Page
-       for (i = 0x04; i != 0; i >>= 1)
-               T55xxWriteBit(Block & i);
-
-       // Now perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
-       // so wait a little more)
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-       SpinDelay(20);
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    uint8_t *dest = (uint8_t *)BigBuf;
+    //int m=0, i=0; //enio adjustment 12/10/14
+    uint32_t m=0, i=0;
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    m = sizeof(BigBuf);
+    // Clear destination buffer before sending the command
+    memset(dest, 128, m);
+    // Connect the A/D to the peak-detected low-frequency path.
+    SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+    // Now set up the SSC to get the ADC samples that are now streaming at us.
+    FpgaSetupSsc();
+
+    LED_D_ON();
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Give it a bit of time for the resonant antenna to settle.
+    // And for the tag to fully power up
+    SpinDelay(150);
+
+    // Now start writting
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    SpinDelayUs(START_GAP);
+
+    // Opcode
+    T55xxWriteBit(1);
+    T55xxWriteBit(0); //Page 0
+    if (PwdMode == 1){
+        // Pwd
+        for (i = 0x80000000; i != 0; i >>= 1)
+            T55xxWriteBit(Pwd & i);
+    }
+    // Lock bit
+    T55xxWriteBit(0);
+    // Block
+    for (i = 0x04; i != 0; i >>= 1)
+        T55xxWriteBit(Block & i);
+
+    // Turn field on to read the response
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Now do the acquisition
+    i = 0;
+    for(;;) {
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+            AT91C_BASE_SSC->SSC_THR = 0x43;
+        }
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+            // we don't care about actual value, only if it's more or less than a
+            // threshold essentially we capture zero crossings for later analysis
+            //                 if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
+            i++;
+            if (i >= m) break;
+        }
+    }
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+    LED_D_OFF();
+    DbpString("DONE!");
+}
+
+// Read card traceability data (page 1)
+void T55xxReadTrace(void){
+    uint8_t *dest = (uint8_t *)BigBuf;
+    int m=0, i=0;
+
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    m = sizeof(BigBuf);
+    // Clear destination buffer before sending the command
+    memset(dest, 128, m);
+    // Connect the A/D to the peak-detected low-frequency path.
+    SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+    // Now set up the SSC to get the ADC samples that are now streaming at us.
+    FpgaSetupSsc();
+
+    LED_D_ON();
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Give it a bit of time for the resonant antenna to settle.
+    // And for the tag to fully power up
+    SpinDelay(150);
+
+    // Now start writting
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+    SpinDelayUs(START_GAP);
+
+    // Opcode
+    T55xxWriteBit(1);
+    T55xxWriteBit(1); //Page 1
+
+    // Turn field on to read the response
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Now do the acquisition
+    i = 0;
+    for(;;) {
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+            AT91C_BASE_SSC->SSC_THR = 0x43;
+        }
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+            i++;
+            if (i >= m) break;
+        }
+    }
+
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+    LED_D_OFF();
+    DbpString("DONE!");
 }
 
+/*-------------- Cloning routines -----------*/
 // Copy HID id to card and setup block 0 config
-void CopyHIDtoT55x7(int hi, int lo)
+void CopyHIDtoT55x7(uint32_t hi2, uint32_t hi, uint32_t lo, uint8_t longFMT)
 {
-       int data1, data2, data3;
-
-       // Ensure no more than 44 bits supplied
-       if (hi>0xFFF) {
-               DbpString("Tags can only have 44 bits.");
-               return;
-       }
-
-       // Build the 3 data blocks for supplied 44bit ID
-       data1 = 0x1D000000; // load preamble
-
-       for (int i=0;i<12;i++) {
-               if (hi & (1<<(11-i)))
-                       data1 |= (1<<(((11-i)*2)+1)); // 1 -> 10
-               else
-                       data1 |= (1<<((11-i)*2)); // 0 -> 01
-       }
-
-       data2 = 0;
-       for (int i=0;i<16;i++) {
-               if (lo & (1<<(31-i)))
-                       data2 |= (1<<(((15-i)*2)+1)); // 1 -> 10
-               else
-                       data2 |= (1<<((15-i)*2)); // 0 -> 01
-       }
-
-       data3 = 0;
-       for (int i=0;i<16;i++) {
-               if (lo & (1<<(15-i)))
-                       data3 |= (1<<(((15-i)*2)+1)); // 1 -> 10
-               else
-                       data3 |= (1<<((15-i)*2)); // 0 -> 01
-       }
-
-       // Program the 3 data blocks for supplied 44bit ID
-       // and the block 0 for HID format
-       T55xxWriteBlock(data1,1);
-       T55xxWriteBlock(data2,2);
-       T55xxWriteBlock(data3,3);
-
-       // Config for HID (RF/50, FSK2a, Maxblock=3)
-       T55xxWriteBlock(T55x7_BITRATE_RF_50    |
-                       T55x7_MODULATION_FSK2a |
-                       3 << T55x7_MAXBLOCK_SHIFT,
-                       0);
-
-       DbpString("DONE!");
+    int data1=0, data2=0, data3=0, data4=0, data5=0, data6=0; //up to six blocks for long format
+    int last_block = 0;
+
+    if (longFMT){
+        // Ensure no more than 84 bits supplied
+        if (hi2>0xFFFFF) {
+            DbpString("Tags can only have 84 bits.");
+            return;
+        }
+        // Build the 6 data blocks for supplied 84bit ID
+        last_block = 6;
+        data1 = 0x1D96A900; // load preamble (1D) & long format identifier (9E manchester encoded)
+        for (int i=0;i<4;i++) {
+            if (hi2 & (1<<(19-i)))
+                data1 |= (1<<(((3-i)*2)+1)); // 1 -> 10
+            else
+                data1 |= (1<<((3-i)*2)); // 0 -> 01
+        }
+
+        data2 = 0;
+        for (int i=0;i<16;i++) {
+            if (hi2 & (1<<(15-i)))
+                data2 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data2 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+
+        data3 = 0;
+        for (int i=0;i<16;i++) {
+            if (hi & (1<<(31-i)))
+                data3 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data3 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+
+        data4 = 0;
+        for (int i=0;i<16;i++) {
+            if (hi & (1<<(15-i)))
+                data4 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data4 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+
+        data5 = 0;
+        for (int i=0;i<16;i++) {
+            if (lo & (1<<(31-i)))
+                data5 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data5 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+
+        data6 = 0;
+        for (int i=0;i<16;i++) {
+            if (lo & (1<<(15-i)))
+                data6 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data6 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+    }
+    else {
+        // Ensure no more than 44 bits supplied
+        if (hi>0xFFF) {
+            DbpString("Tags can only have 44 bits.");
+            return;
+        }
+
+        // Build the 3 data blocks for supplied 44bit ID
+        last_block = 3;
+
+        data1 = 0x1D000000; // load preamble
+
+        for (int i=0;i<12;i++) {
+            if (hi & (1<<(11-i)))
+                data1 |= (1<<(((11-i)*2)+1)); // 1 -> 10
+            else
+                data1 |= (1<<((11-i)*2)); // 0 -> 01
+        }
+
+        data2 = 0;
+        for (int i=0;i<16;i++) {
+            if (lo & (1<<(31-i)))
+                data2 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data2 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+
+        data3 = 0;
+        for (int i=0;i<16;i++) {
+            if (lo & (1<<(15-i)))
+                data3 |= (1<<(((15-i)*2)+1)); // 1 -> 10
+            else
+                data3 |= (1<<((15-i)*2)); // 0 -> 01
+        }
+    }
+
+    LED_D_ON();
+    // Program the data blocks for supplied ID
+    // and the block 0 for HID format
+    T55xxWriteBlock(data1,1,0,0);
+    T55xxWriteBlock(data2,2,0,0);
+    T55xxWriteBlock(data3,3,0,0);
+
+    if (longFMT) { // if long format there are 6 blocks
+        T55xxWriteBlock(data4,4,0,0);
+        T55xxWriteBlock(data5,5,0,0);
+        T55xxWriteBlock(data6,6,0,0);
+    }
+
+    // Config for HID (RF/50, FSK2a, Maxblock=3 for short/6 for long)
+    T55xxWriteBlock(T55x7_BITRATE_RF_50    |
+                    T55x7_MODULATION_FSK2a |
+                    last_block << T55x7_MAXBLOCK_SHIFT,
+                    0,0,0);
+
+    LED_D_OFF();
+
+    DbpString("DONE!");
+}
+
+void CopyIOtoT55x7(uint32_t hi, uint32_t lo, uint8_t longFMT)
+{
+    int data1=0, data2=0; //up to six blocks for long format
+
+    data1 = hi;  // load preamble
+    data2 = lo;
+
+    LED_D_ON();
+    // Program the data blocks for supplied ID
+    // and the block 0 for HID format
+    T55xxWriteBlock(data1,1,0,0);
+    T55xxWriteBlock(data2,2,0,0);
+
+    //Config Block
+    T55xxWriteBlock(0x00147040,0,0,0);
+    LED_D_OFF();
+
+    DbpString("DONE!");
 }
 
 // Define 9bit header for EM410x tags
@@ -1149,126 +1222,631 @@ void CopyHIDtoT55x7(int hi, int lo)
 
 void WriteEM410x(uint32_t card, uint32_t id_hi, uint32_t id_lo)
 {
-       int i, id_bit;
-       uint64_t id = EM410X_HEADER;
-       uint64_t rev_id = 0;    // reversed ID
-       int c_parity[4];        // column parity
-       int r_parity = 0;       // row parity
-
-       // Reverse ID bits given as parameter (for simpler operations)
-       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
-               if (i < 32) {
-                       rev_id = (rev_id << 1) | (id_lo & 1);
-                       id_lo >>= 1;
-               } else {
-                       rev_id = (rev_id << 1) | (id_hi & 1);
-                       id_hi >>= 1;
-               }
-       }
-
-       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
-               id_bit = rev_id & 1;
-
-               if (i % 4 == 0) {
-                       // Don't write row parity bit at start of parsing
-                       if (i)
-                               id = (id << 1) | r_parity;
-                       // Start counting parity for new row
-                       r_parity = id_bit;
-               } else {
-                       // Count row parity
-                       r_parity ^= id_bit;
-               }
-
-               // First elements in column?
-               if (i < 4)
-                       // Fill out first elements
-                       c_parity[i] = id_bit;
-               else
-                       // Count column parity
-                       c_parity[i % 4] ^= id_bit;
-
-               // Insert ID bit
-               id = (id << 1) | id_bit;
-               rev_id >>= 1;
-       }
-
-       // Insert parity bit of last row
-       id = (id << 1) | r_parity;
-
-       // Fill out column parity at the end of tag
-       for (i = 0; i < 4; ++i)
-               id = (id << 1) | c_parity[i];
-
-       // Add stop bit
-       id <<= 1;
-
-       Dbprintf("Started writing %s tag ...", card ? "T55x7":"T5555");
-       LED_D_ON();
-
-       // Write EM410x ID
-       T55xxWriteBlock((uint32_t)(id >> 32), 1);
-       T55xxWriteBlock((uint32_t)id, 2);
-
-       // Config for EM410x (RF/64, Manchester, Maxblock=2)
-       if (card)
-               // Writing configuration for T55x7 tag
-               T55xxWriteBlock(T55x7_BITRATE_RF_64         |
-                               T55x7_MODULATION_MANCHESTER |
-                               2 << T55x7_MAXBLOCK_SHIFT,
-                               0);
-       else
-               // Writing configuration for T5555(Q5) tag
-               T55xxWriteBlock(0x1F << T5555_BITRATE_SHIFT |
-                               T5555_MODULATION_MANCHESTER   |
-                               2 << T5555_MAXBLOCK_SHIFT,
-                               0);
-
-       LED_D_OFF();
-       Dbprintf("Tag %s written with 0x%08x%08x\n", card ? "T55x7":"T5555",
-                                       (uint32_t)(id >> 32), (uint32_t)id);
+    int i, id_bit;
+    uint64_t id = EM410X_HEADER;
+    uint64_t rev_id = 0;       // reversed ID
+    int c_parity[4];   // column parity
+    int r_parity = 0;  // row parity
+    uint32_t clock = 0;
+
+    // Reverse ID bits given as parameter (for simpler operations)
+    for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+        if (i < 32) {
+            rev_id = (rev_id << 1) | (id_lo & 1);
+            id_lo >>= 1;
+        } else {
+            rev_id = (rev_id << 1) | (id_hi & 1);
+            id_hi >>= 1;
+        }
+    }
+
+    for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+        id_bit = rev_id & 1;
+
+        if (i % 4 == 0) {
+            // Don't write row parity bit at start of parsing
+            if (i)
+                id = (id << 1) | r_parity;
+            // Start counting parity for new row
+            r_parity = id_bit;
+        } else {
+            // Count row parity
+            r_parity ^= id_bit;
+        }
+
+        // First elements in column?
+        if (i < 4)
+            // Fill out first elements
+            c_parity[i] = id_bit;
+        else
+            // Count column parity
+            c_parity[i % 4] ^= id_bit;
+
+        // Insert ID bit
+        id = (id << 1) | id_bit;
+        rev_id >>= 1;
+    }
+
+    // Insert parity bit of last row
+    id = (id << 1) | r_parity;
+
+    // Fill out column parity at the end of tag
+    for (i = 0; i < 4; ++i)
+        id = (id << 1) | c_parity[i];
+
+    // Add stop bit
+    id <<= 1;
+
+    Dbprintf("Started writing %s tag ...", card ? "T55x7":"T5555");
+    LED_D_ON();
+
+    // Write EM410x ID
+    T55xxWriteBlock((uint32_t)(id >> 32), 1, 0, 0);
+    T55xxWriteBlock((uint32_t)id, 2, 0, 0);
+
+    // Config for EM410x (RF/64, Manchester, Maxblock=2)
+    if (card) {
+        // Clock rate is stored in bits 8-15 of the card value
+        clock = (card & 0xFF00) >> 8;
+        Dbprintf("Clock rate: %d", clock);
+        switch (clock)
+        {
+        case 32:
+            clock = T55x7_BITRATE_RF_32;
+            break;
+        case 16:
+            clock = T55x7_BITRATE_RF_16;
+            break;
+        case 0:
+            // A value of 0 is assumed to be 64 for backwards-compatibility
+            // Fall through...
+        case 64:
+            clock = T55x7_BITRATE_RF_64;
+            break;
+        default:
+            Dbprintf("Invalid clock rate: %d", clock);
+            return;
+        }
+
+        // Writing configuration for T55x7 tag
+        T55xxWriteBlock(clock      |
+                        T55x7_MODULATION_MANCHESTER |
+                        2 << T55x7_MAXBLOCK_SHIFT,
+                        0, 0, 0);
+    }
+    else
+        // Writing configuration for T5555(Q5) tag
+        T55xxWriteBlock(0x1F << T5555_BITRATE_SHIFT |
+                        T5555_MODULATION_MANCHESTER   |
+                        2 << T5555_MAXBLOCK_SHIFT,
+                        0, 0, 0);
+
+    LED_D_OFF();
+    Dbprintf("Tag %s written with 0x%08x%08x\n", card ? "T55x7":"T5555",
+             (uint32_t)(id >> 32), (uint32_t)id);
 }
 
 // Clone Indala 64-bit tag by UID to T55x7
 void CopyIndala64toT55x7(int hi, int lo)
 {
 
-       //Program the 2 data blocks for supplied 64bit UID
-       // and the block 0 for Indala64 format
-       T55xxWriteBlock(hi,1);
-       T55xxWriteBlock(lo,2);
-       //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=2)
-       T55xxWriteBlock(T55x7_BITRATE_RF_32    |
-                       T55x7_MODULATION_PSK1 |
-                       2 << T55x7_MAXBLOCK_SHIFT,
-                       0);
-       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=2;Inverse data)
-//     T5567WriteBlock(0x603E1042,0);
+    //Program the 2 data blocks for supplied 64bit UID
+    // and the block 0 for Indala64 format
+    T55xxWriteBlock(hi,1,0,0);
+    T55xxWriteBlock(lo,2,0,0);
+    //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=2)
+    T55xxWriteBlock(T55x7_BITRATE_RF_32    |
+                    T55x7_MODULATION_PSK1 |
+                    2 << T55x7_MAXBLOCK_SHIFT,
+                    0, 0, 0);
+    //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=2;Inverse data)
+    // T5567WriteBlock(0x603E1042,0);
 
-       DbpString("DONE!");
+    DbpString("DONE!");
 
-}      
+}
 
 void CopyIndala224toT55x7(int uid1, int uid2, int uid3, int uid4, int uid5, int uid6, int uid7)
 {
 
-       //Program the 7 data blocks for supplied 224bit UID
-       // and the block 0 for Indala224 format
-       T55xxWriteBlock(uid1,1);
-       T55xxWriteBlock(uid2,2);
-       T55xxWriteBlock(uid3,3);
-       T55xxWriteBlock(uid4,4);
-       T55xxWriteBlock(uid5,5);
-       T55xxWriteBlock(uid6,6);
-       T55xxWriteBlock(uid7,7);
-       //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=7)
-       T55xxWriteBlock(T55x7_BITRATE_RF_32    |
-                       T55x7_MODULATION_PSK1 |
-                       7 << T55x7_MAXBLOCK_SHIFT,
-                       0);
-       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=7;Inverse data)
-//     T5567WriteBlock(0x603E10E2,0);
-
-       DbpString("DONE!");
+    //Program the 7 data blocks for supplied 224bit UID
+    // and the block 0 for Indala224 format
+    T55xxWriteBlock(uid1,1,0,0);
+    T55xxWriteBlock(uid2,2,0,0);
+    T55xxWriteBlock(uid3,3,0,0);
+    T55xxWriteBlock(uid4,4,0,0);
+    T55xxWriteBlock(uid5,5,0,0);
+    T55xxWriteBlock(uid6,6,0,0);
+    T55xxWriteBlock(uid7,7,0,0);
+    //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=7)
+    T55xxWriteBlock(T55x7_BITRATE_RF_32    |
+                    T55x7_MODULATION_PSK1 |
+                    7 << T55x7_MAXBLOCK_SHIFT,
+                    0,0,0);
+    //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=7;Inverse data)
+    // T5567WriteBlock(0x603E10E2,0);
+
+    DbpString("DONE!");
+
+}
+
+
+#define abs(x) ( ((x)<0) ? -(x) : (x) )
+#define max(x,y) ( x<y ? y:x)
+
+int DemodPCF7931(uint8_t **outBlocks) {
+    uint8_t BitStream[256];
+    uint8_t Blocks[8][16];
+    uint8_t *GraphBuffer = (uint8_t *)BigBuf;
+    int GraphTraceLen = sizeof(BigBuf);
+    int i, j, lastval, bitidx, half_switch;
+    int clock = 64;
+    int tolerance = clock / 8;
+    int pmc, block_done;
+    int lc, warnings = 0;
+    int num_blocks = 0;
+    int lmin=128, lmax=128;
+    uint8_t dir;
+
+    AcquireRawAdcSamples125k(0);
+
+    lmin = 64;
+    lmax = 192;
+
+    i = 2;
+
+    /* Find first local max/min */
+    if(GraphBuffer[1] > GraphBuffer[0]) {
+        while(i < GraphTraceLen) {
+            if( !(GraphBuffer[i] > GraphBuffer[i-1]) && GraphBuffer[i] > lmax)
+                break;
+            i++;
+        }
+        dir = 0;
+    }
+    else {
+        while(i < GraphTraceLen) {
+            if( !(GraphBuffer[i] < GraphBuffer[i-1]) && GraphBuffer[i] < lmin)
+                break;
+            i++;
+        }
+        dir = 1;
+    }
+
+    lastval = i++;
+    half_switch = 0;
+    pmc = 0;
+    block_done = 0;
+
+    for (bitidx = 0; i < GraphTraceLen; i++)
+    {
+        if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
+        {
+            lc = i - lastval;
+            lastval = i;
+
+            // Switch depending on lc length:
+            // Tolerance is 1/8 of clock rate (arbitrary)
+            if (abs(lc-clock/4) < tolerance) {
+                // 16T0
+                if((i - pmc) == lc) { /* 16T0 was previous one */
+                    /* It's a PMC ! */
+                    i += (128+127+16+32+33+16)-1;
+                    lastval = i;
+                    pmc = 0;
+                    block_done = 1;
+                }
+                else {
+                    pmc = i;
+                }
+            } else if (abs(lc-clock/2) < tolerance) {
+                // 32TO
+                if((i - pmc) == lc) { /* 16T0 was previous one */
+                    /* It's a PMC ! */
+                    i += (128+127+16+32+33)-1;
+                    lastval = i;
+                    pmc = 0;
+                    block_done = 1;
+                }
+                else if(half_switch == 1) {
+                    BitStream[bitidx++] = 0;
+                    half_switch = 0;
+                }
+                else
+                    half_switch++;
+            } else if (abs(lc-clock) < tolerance) {
+                // 64TO
+                BitStream[bitidx++] = 1;
+            } else {
+                // Error
+                warnings++;
+                if (warnings > 10)
+                {
+                    Dbprintf("Error: too many detection errors, aborting.");
+                    return 0;
+                }
+            }
+
+            if(block_done == 1) {
+                if(bitidx == 128) {
+                    for(j=0; j<16; j++) {
+                        Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
+                                64*BitStream[j*8+6]+
+                                32*BitStream[j*8+5]+
+                                16*BitStream[j*8+4]+
+                                8*BitStream[j*8+3]+
+                                4*BitStream[j*8+2]+
+                                2*BitStream[j*8+1]+
+                                BitStream[j*8];
+                    }
+                    num_blocks++;
+                }
+                bitidx = 0;
+                block_done = 0;
+                half_switch = 0;
+            }
+            if(i < GraphTraceLen)
+            {
+                if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
+                else dir = 1;
+            }
+        }
+        if(bitidx==255)
+            bitidx=0;
+        warnings = 0;
+        if(num_blocks == 4) break;
+    }
+    memcpy(outBlocks, Blocks, 16*num_blocks);
+    return num_blocks;
+}
+
+int IsBlock0PCF7931(uint8_t *Block) {
+    // Assume RFU means 0 :)
+    if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
+        return 1;
+    if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
+        return 1;
+    return 0;
+}
+
+int IsBlock1PCF7931(uint8_t *Block) {
+    // Assume RFU means 0 :)
+    if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
+        if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
+            return 1;
+
+    return 0;
+}
+
+#define ALLOC 16
+
+void ReadPCF7931() {
+    uint8_t Blocks[8][17];
+    uint8_t tmpBlocks[4][16];
+    int i, j, ind, ind2, n;
+    int num_blocks = 0;
+    int max_blocks = 8;
+    int ident = 0;
+    int error = 0;
+    int tries = 0;
+
+    memset(Blocks, 0, 8*17*sizeof(uint8_t));
+
+    do {
+        memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
+        n = DemodPCF7931((uint8_t**)tmpBlocks);
+        if(!n)
+            error++;
+        if(error==10 && num_blocks == 0) {
+            Dbprintf("Error, no tag or bad tag");
+            return;
+        }
+        else if (tries==20 || error==10) {
+            Dbprintf("Error reading the tag");
+            Dbprintf("Here is the partial content");
+            goto end;
+        }
+
+        for(i=0; i<n; i++)
+            Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
+                     tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
+                    tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
+        if(!ident) {
+            for(i=0; i<n; i++) {
+                if(IsBlock0PCF7931(tmpBlocks[i])) {
+                    // Found block 0 ?
+                    if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
+                        // Found block 1!
+                        // \o/
+                        ident = 1;
+                        memcpy(Blocks[0], tmpBlocks[i], 16);
+                        Blocks[0][ALLOC] = 1;
+                        memcpy(Blocks[1], tmpBlocks[i+1], 16);
+                        Blocks[1][ALLOC] = 1;
+                        max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
+                        // Debug print
+                        Dbprintf("(dbg) Max blocks: %d", max_blocks);
+                        num_blocks = 2;
+                        // Handle following blocks
+                        for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
+                            if(j==n) j=0;
+                            if(j==i) break;
+                            memcpy(Blocks[ind2], tmpBlocks[j], 16);
+                            Blocks[ind2][ALLOC] = 1;
+                        }
+                        break;
+                    }
+                }
+            }
+        }
+        else {
+            for(i=0; i<n; i++) { // Look for identical block in known blocks
+                if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
+                    for(j=0; j<max_blocks; j++) {
+                        if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
+                            // Found an identical block
+                            for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
+                                if(ind2 < 0)
+                                    ind2 = max_blocks;
+                                if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
+                                    // Dbprintf("Tmp %d -> Block %d", ind, ind2);
+                                    memcpy(Blocks[ind2], tmpBlocks[ind], 16);
+                                    Blocks[ind2][ALLOC] = 1;
+                                    num_blocks++;
+                                    if(num_blocks == max_blocks) goto end;
+                                }
+                            }
+                            for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
+                                if(ind2 > max_blocks)
+                                    ind2 = 0;
+                                if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
+                                    // Dbprintf("Tmp %d -> Block %d", ind, ind2);
+                                    memcpy(Blocks[ind2], tmpBlocks[ind], 16);
+                                    Blocks[ind2][ALLOC] = 1;
+                                    num_blocks++;
+                                    if(num_blocks == max_blocks) goto end;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        tries++;
+        if (BUTTON_PRESS()) return;
+    } while (num_blocks != max_blocks);
+end:
+    Dbprintf("-----------------------------------------");
+    Dbprintf("Memory content:");
+    Dbprintf("-----------------------------------------");
+    for(i=0; i<max_blocks; i++) {
+        if(Blocks[i][ALLOC]==1)
+            Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
+                     Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
+                    Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
+        else
+            Dbprintf("<missing block %d>", i);
+    }
+    Dbprintf("-----------------------------------------");
+
+    return ;
+}
+
+
+//-----------------------------------
+// EM4469 / EM4305 routines
+//-----------------------------------
+#define FWD_CMD_LOGIN 0xC //including the even parity, binary mirrored
+#define FWD_CMD_WRITE 0xA
+#define FWD_CMD_READ 0x9
+#define FWD_CMD_DISABLE 0x5
+
+
+uint8_t forwardLink_data[64]; //array of forwarded bits
+uint8_t * forward_ptr; //ptr for forward message preparation
+uint8_t fwd_bit_sz; //forwardlink bit counter
+uint8_t * fwd_write_ptr; //forwardlink bit pointer
+
+//====================================================================
+// prepares command bits
+// see EM4469 spec
+//====================================================================
+//--------------------------------------------------------------------
+uint8_t Prepare_Cmd( uint8_t cmd ) {
+    //--------------------------------------------------------------------
+
+    *forward_ptr++ = 0; //start bit
+    *forward_ptr++ = 0; //second pause for 4050 code
+
+    *forward_ptr++ = cmd;
+    cmd >>= 1;
+    *forward_ptr++ = cmd;
+    cmd >>= 1;
+    *forward_ptr++ = cmd;
+    cmd >>= 1;
+    *forward_ptr++ = cmd;
+
+    return 6; //return number of emited bits
+}
+
+//====================================================================
+// prepares address bits
+// see EM4469 spec
+//====================================================================
+
+//--------------------------------------------------------------------
+uint8_t Prepare_Addr( uint8_t addr ) {
+    //--------------------------------------------------------------------
+
+    register uint8_t line_parity;
+
+    uint8_t i;
+    line_parity = 0;
+    for(i=0;i<6;i++) {
+        *forward_ptr++ = addr;
+        line_parity ^= addr;
+        addr >>= 1;
+    }
+
+    *forward_ptr++ = (line_parity & 1);
+
+    return 7; //return number of emited bits
+}
+
+//====================================================================
+// prepares data bits intreleaved with parity bits
+// see EM4469 spec
+//====================================================================
+
+//--------------------------------------------------------------------
+uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
+    //--------------------------------------------------------------------
+
+    register uint8_t line_parity;
+    register uint8_t column_parity;
+    register uint8_t i, j;
+    register uint16_t data;
+
+    data = data_low;
+    column_parity = 0;
+
+    for(i=0; i<4; i++) {
+        line_parity = 0;
+        for(j=0; j<8; j++) {
+            line_parity ^= data;
+            column_parity ^= (data & 1) << j;
+            *forward_ptr++ = data;
+            data >>= 1;
+        }
+        *forward_ptr++ = line_parity;
+        if(i == 1)
+            data = data_hi;
+    }
+
+    for(j=0; j<8; j++) {
+        *forward_ptr++ = column_parity;
+        column_parity >>= 1;
+    }
+    *forward_ptr = 0;
+
+    return 45; //return number of emited bits
+}
+
+//====================================================================
+// Forward Link send function
+// Requires: forwarLink_data filled with valid bits (1 bit per byte)
+// fwd_bit_count set with number of bits to be sent
+//====================================================================
+void SendForward(uint8_t fwd_bit_count) {
+
+    fwd_write_ptr = forwardLink_data;
+    fwd_bit_sz = fwd_bit_count;
+
+    LED_D_ON();
+
+    //Field on
+    FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+    // Give it a bit of time for the resonant antenna to settle.
+    // And for the tag to fully power up
+    SpinDelay(150);
+
+    // force 1st mod pulse (start gap must be longer for 4305)
+    fwd_bit_sz--; //prepare next bit modulation
+    fwd_write_ptr++;
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+    SpinDelayUs(55*8); //55 cycles off (8us each)for 4305
+    FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+    SpinDelayUs(16*8); //16 cycles on (8us each)
+
+    // now start writting
+    while(fwd_bit_sz-- > 0) { //prepare next bit modulation
+        if(((*fwd_write_ptr++) & 1) == 1)
+            SpinDelayUs(32*8); //32 cycles at 125Khz (8us each)
+        else {
+            //These timings work for 4469/4269/4305 (with the 55*8 above)
+            FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+            SpinDelayUs(23*8); //16-4 cycles off (8us each)
+            FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+            FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+            SpinDelayUs(9*8); //16 cycles on (8us each)
+        }
+    }
+}
+
+void EM4xLogin(uint32_t Password) {
+
+    uint8_t fwd_bit_count;
+
+    forward_ptr = forwardLink_data;
+    fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
+    fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
+
+    SendForward(fwd_bit_count);
+
+    //Wait for command to complete
+    SpinDelay(20);
+
+}
+
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+    uint8_t fwd_bit_count;
+    uint8_t *dest = (uint8_t *)BigBuf;
+    int m=0, i=0;
+
+    //If password mode do login
+    if (PwdMode == 1) EM4xLogin(Pwd);
+
+    forward_ptr = forwardLink_data;
+    fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
+    fwd_bit_count += Prepare_Addr( Address );
+
+    m = sizeof(BigBuf);
+    // Clear destination buffer before sending the command
+    memset(dest, 128, m);
+    // Connect the A/D to the peak-detected low-frequency path.
+    SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+    // Now set up the SSC to get the ADC samples that are now streaming at us.
+    FpgaSetupSsc();
+
+    SendForward(fwd_bit_count);
+
+    // Now do the acquisition
+    i = 0;
+    for(;;) {
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+            AT91C_BASE_SSC->SSC_THR = 0x43;
+        }
+        if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+            dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+            i++;
+            if (i >= m) break;
+        }
+    }
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+    LED_D_OFF();
+}
+
+void EM4xWriteWord(uint32_t Data, uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+    uint8_t fwd_bit_count;
+
+    //If password mode do login
+    if (PwdMode == 1) EM4xLogin(Pwd);
+
+    forward_ptr = forwardLink_data;
+    fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
+    fwd_bit_count += Prepare_Addr( Address );
+    fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+    SendForward(fwd_bit_count);
 
+    //Wait for write to complete
+    SpinDelay(20);
+    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+    LED_D_OFF();
 }
Impressum, Datenschutz