git.zerfleddert.de Git - proxmark3-svn/blob - armsrc/lfops.c

   1 //-----------------------------------------------------------------------------
   2 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   3 // at your option, any later version. See the LICENSE.txt file for the text of
   4 // the license.
   5 //-----------------------------------------------------------------------------
   6 // Miscellaneous routines for low frequency tag operations.
   7 // Tags supported here so far are Texas Instruments (TI), HID
   8 // Also routines for raw mode reading/simulating of LF waveform
   9 //-----------------------------------------------------------------------------
  10
  11 #include "proxmark3.h"
  12 #include "apps.h"
  13 #include "util.h"
  14 #include "hitag2.h"
  15 #include "crc16.h"
  16 #include "string.h"
  17
  18 void LFSetupFPGAForADC(int divisor, bool lf_field)
  19 {
  20         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
  21         if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
  22                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
  23         else if (divisor == 0)
  24                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
  25         else
  26                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
  27
  28         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
  29
  30         // Connect the A/D to the peak-detected low-frequency path.
  31         SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
  32         // Give it a bit of time for the resonant antenna to settle.
  33         SpinDelay(50);
  34         // Now set up the SSC to get the ADC samples that are now streaming at us.
  35         FpgaSetupSsc();
  36 }
  37
  38 void AcquireRawAdcSamples125k(int divisor)
  39 {
  40         LFSetupFPGAForADC(divisor, true);
  41         DoAcquisition125k(-1);
  42 }
  43
  44 void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
  45 {
  46         LFSetupFPGAForADC(divisor, false);
  47         DoAcquisition125k(trigger_threshold);
  48 }
  49
  50 // split into two routines so we can avoid timing issues after sending commands //
  51 void DoAcquisition125k(int trigger_threshold)
  52 {
  53         uint8_t *dest = (uint8_t *)BigBuf;
  54         int n = sizeof(BigBuf);
  55         int i;
  56
  57         memset(dest, 0, n);
  58         i = 0;
  59         for(;;) {
  60                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
  61                         AT91C_BASE_SSC->SSC_THR = 0x43;
  62                         LED_D_ON();
  63                 }
  64                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
  65                         dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
  66                         LED_D_OFF();
  67                         if (trigger_threshold != -1 && dest[i] < trigger_threshold)
  68                                 continue;
  69                         else
  70                                 trigger_threshold = -1;
  71                         if (++i >= n) break;
  72                 }
  73         }
  74         Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
  75                         dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
  76 }
  77
  78 void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)
  79 {
  80         int at134khz;
  81
  82         /* Make sure the tag is reset */
  83         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
  84         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
  85         SpinDelay(2500);
  86
  87         // see if 'h' was specified
  88         if (command[strlen((char *) command) - 1] == 'h')
  89                 at134khz = TRUE;
  90         else
  91                 at134khz = FALSE;
  92
  93         if (at134khz)
  94                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
  95         else
  96                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
  97
  98         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
  99
 100         // Give it a bit of time for the resonant antenna to settle.
 101         SpinDelay(50);
 102         // And a little more time for the tag to fully power up
 103         SpinDelay(2000);
 104
 105         // Now set up the SSC to get the ADC samples that are now streaming at us.
 106         FpgaSetupSsc();
 107
 108         // now modulate the reader field
 109         while(*command != '\0' && *command != ' ') {
 110                 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 111                 LED_D_OFF();
 112                 SpinDelayUs(delay_off);
 113                 if (at134khz)
 114                         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 115                 else
 116                         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 117
 118                 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 119                 LED_D_ON();
 120                 if(*(command++) == '0')
 121                         SpinDelayUs(period_0);
 122                 else
 123                         SpinDelayUs(period_1);
 124         }
 125         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 126         LED_D_OFF();
 127         SpinDelayUs(delay_off);
 128         if (at134khz)
 129                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 130         else
 131                 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 132
 133         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 134
 135         // now do the read
 136         DoAcquisition125k(-1);
 137 }
 138
 139 /* blank r/w tag data stream
 140 ...0000000000000000 01111111
 141 1010101010101010101010101010101010101010101010101010101010101010
 142 0011010010100001
 143 01111111
 144 101010101010101[0]000...
 145
 146 [5555fe852c5555555555555555fe0000]
 147 */
 148 void ReadTItag(void)
 149 {
 150         // some hardcoded initial params
 151         // when we read a TI tag we sample the zerocross line at 2Mhz
 152         // TI tags modulate a 1 as 16 cycles of 123.2Khz
 153         // TI tags modulate a 0 as 16 cycles of 134.2Khz
 154         #define FSAMPLE 2000000
 155         #define FREQLO 123200
 156         #define FREQHI 134200
 157
 158         signed char *dest = (signed char *)BigBuf;
 159         int n = sizeof(BigBuf);
 160 //      int *dest = GraphBuffer;
 161 //      int n = GraphTraceLen;
 162
 163         // 128 bit shift register [shift3:shift2:shift1:shift0]
 164         uint32_t shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
 165
 166         int i, cycles=0, samples=0;
 167         // how many sample points fit in 16 cycles of each frequency
 168         uint32_t sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
 169         // when to tell if we're close enough to one freq or another
 170         uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
 171
 172         // TI tags charge at 134.2Khz
 173         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 174         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 175
 176         // Place FPGA in passthrough mode, in this mode the CROSS_LO line
 177         // connects to SSP_DIN and the SSP_DOUT logic level controls
 178         // whether we're modulating the antenna (high)
 179         // or listening to the antenna (low)
 180         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
 181
 182         // get TI tag data into the buffer
 183         AcquireTiType();
 184
 185         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 186
 187         for (i=0; i<n-1; i++) {
 188                 // count cycles by looking for lo to hi zero crossings
 189                 if ( (dest[i]<0) && (dest[i+1]>0) ) {
 190                         cycles++;
 191                         // after 16 cycles, measure the frequency
 192                         if (cycles>15) {
 193                                 cycles=0;
 194                                 samples=i-samples; // number of samples in these 16 cycles
 195
 196                                 // TI bits are coming to us lsb first so shift them
 197                                 // right through our 128 bit right shift register
 198                           shift0 = (shift0>>1) | (shift1 << 31);
 199                           shift1 = (shift1>>1) | (shift2 << 31);
 200                           shift2 = (shift2>>1) | (shift3 << 31);
 201                           shift3 >>= 1;
 202
 203                                 // check if the cycles fall close to the number
 204                                 // expected for either the low or high frequency
 205                                 if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {
 206                                         // low frequency represents a 1
 207                                         shift3 |= (1<<31);
 208                                 } else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {
 209                                         // high frequency represents a 0
 210                                 } else {
 211                                         // probably detected a gay waveform or noise
 212                                         // use this as gaydar or discard shift register and start again
 213                                         shift3 = shift2 = shift1 = shift0 = 0;
 214                                 }
 215                                 samples = i;
 216
 217                                 // for each bit we receive, test if we've detected a valid tag
 218
 219                                 // if we see 17 zeroes followed by 6 ones, we might have a tag
 220                                 // remember the bits are backwards
 221                                 if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {
 222                                         // if start and end bytes match, we have a tag so break out of the loop
 223                                         if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {
 224                                                 cycles = 0xF0B; //use this as a flag (ugly but whatever)
 225                                                 break;
 226                                         }
 227                                 }
 228                         }
 229                 }
 230         }
 231
 232         // if flag is set we have a tag
 233         if (cycles!=0xF0B) {
 234                 DbpString("Info: No valid tag detected.");
 235         } else {
 236           // put 64 bit data into shift1 and shift0
 237           shift0 = (shift0>>24) | (shift1 << 8);
 238           shift1 = (shift1>>24) | (shift2 << 8);
 239
 240                 // align 16 bit crc into lower half of shift2
 241           shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
 242
 243                 // if r/w tag, check ident match
 244                 if ( shift3&(1<<15) ) {
 245                         DbpString("Info: TI tag is rewriteable");
 246                         // only 15 bits compare, last bit of ident is not valid
 247                         if ( ((shift3>>16)^shift0)&0x7fff ) {
 248                                 DbpString("Error: Ident mismatch!");
 249                         } else {
 250                                 DbpString("Info: TI tag ident is valid");
 251                         }
 252                 } else {
 253                         DbpString("Info: TI tag is readonly");
 254                 }
 255
 256                 // WARNING the order of the bytes in which we calc crc below needs checking
 257                 // i'm 99% sure the crc algorithm is correct, but it may need to eat the
 258                 // bytes in reverse or something
 259                 // calculate CRC
 260                 uint32_t crc=0;
 261
 262                 crc = update_crc16(crc, (shift0)&0xff);
 263                 crc = update_crc16(crc, (shift0>>8)&0xff);
 264                 crc = update_crc16(crc, (shift0>>16)&0xff);
 265                 crc = update_crc16(crc, (shift0>>24)&0xff);
 266                 crc = update_crc16(crc, (shift1)&0xff);
 267                 crc = update_crc16(crc, (shift1>>8)&0xff);
 268                 crc = update_crc16(crc, (shift1>>16)&0xff);
 269                 crc = update_crc16(crc, (shift1>>24)&0xff);
 270
 271                 Dbprintf("Info: Tag data: %x%08x, crc=%x",
 272                         (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
 273                 if (crc != (shift2&0xffff)) {
 274                         Dbprintf("Error: CRC mismatch, expected %x", (unsigned int)crc);
 275                 } else {
 276                         DbpString("Info: CRC is good");
 277                 }
 278         }
 279 }
 280
 281 void WriteTIbyte(uint8_t b)
 282 {
 283         int i = 0;
 284
 285         // modulate 8 bits out to the antenna
 286         for (i=0; i<8; i++)
 287         {
 288                 if (b&(1<<i)) {
 289                         // stop modulating antenna
 290                         LOW(GPIO_SSC_DOUT);
 291                         SpinDelayUs(1000);
 292                         // modulate antenna
 293                         HIGH(GPIO_SSC_DOUT);
 294                         SpinDelayUs(1000);
 295                 } else {
 296                         // stop modulating antenna
 297                         LOW(GPIO_SSC_DOUT);
 298                         SpinDelayUs(300);
 299                         // modulate antenna
 300                         HIGH(GPIO_SSC_DOUT);
 301                         SpinDelayUs(1700);
 302                 }
 303         }
 304 }
 305
 306 void AcquireTiType(void)
 307 {
 308         int i, j, n;
 309         // tag transmission is <20ms, sampling at 2M gives us 40K samples max
 310         // each sample is 1 bit stuffed into a uint32_t so we need 1250 uint32_t
 311         #define TIBUFLEN 1250
 312
 313         // clear buffer
 314         memset(BigBuf,0,sizeof(BigBuf));
 315
 316         // Set up the synchronous serial port
 317         AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;
 318         AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN;
 319
 320         // steal this pin from the SSP and use it to control the modulation
 321         AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
 322         AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
 323
 324         AT91C_BASE_SSC->SSC_CR = AT91C_SSC_SWRST;
 325         AT91C_BASE_SSC->SSC_CR = AT91C_SSC_RXEN | AT91C_SSC_TXEN;
 326
 327         // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long
 328         // 48/2 = 24 MHz clock must be divided by 12
 329         AT91C_BASE_SSC->SSC_CMR = 12;
 330
 331         AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(0);
 332         AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(32) | AT91C_SSC_MSBF;
 333         AT91C_BASE_SSC->SSC_TCMR = 0;
 334         AT91C_BASE_SSC->SSC_TFMR = 0;
 335
 336         LED_D_ON();
 337
 338         // modulate antenna
 339         HIGH(GPIO_SSC_DOUT);
 340
 341         // Charge TI tag for 50ms.
 342         SpinDelay(50);
 343
 344         // stop modulating antenna and listen
 345         LOW(GPIO_SSC_DOUT);
 346
 347         LED_D_OFF();
 348
 349         i = 0;
 350         for(;;) {
 351                 if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
 352                         BigBuf[i] = AT91C_BASE_SSC->SSC_RHR;    // store 32 bit values in buffer
 353                         i++; if(i >= TIBUFLEN) break;
 354                 }
 355                 WDT_HIT();
 356         }
 357
 358         // return stolen pin to SSP
 359         AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
 360         AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
 361
 362         char *dest = (char *)BigBuf;
 363         n = TIBUFLEN*32;
 364         // unpack buffer
 365         for (i=TIBUFLEN-1; i>=0; i--) {
 366                 for (j=0; j<32; j++) {
 367                         if(BigBuf[i] & (1 << j)) {
 368                                 dest[--n] = 1;
 369                         } else {
 370                                 dest[--n] = -1;
 371                         }
 372                 }
 373         }
 374 }
 375
 376 // arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc
 377 // if crc provided, it will be written with the data verbatim (even if bogus)
 378 // if not provided a valid crc will be computed from the data and written.
 379 void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
 380 {
 381         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 382         if(crc == 0) {
 383                 crc = update_crc16(crc, (idlo)&0xff);
 384                 crc = update_crc16(crc, (idlo>>8)&0xff);
 385                 crc = update_crc16(crc, (idlo>>16)&0xff);
 386                 crc = update_crc16(crc, (idlo>>24)&0xff);
 387                 crc = update_crc16(crc, (idhi)&0xff);
 388                 crc = update_crc16(crc, (idhi>>8)&0xff);
 389                 crc = update_crc16(crc, (idhi>>16)&0xff);
 390                 crc = update_crc16(crc, (idhi>>24)&0xff);
 391         }
 392         Dbprintf("Writing to tag: %x%08x, crc=%x",
 393                 (unsigned int) idhi, (unsigned int) idlo, crc);
 394
 395         // TI tags charge at 134.2Khz
 396         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 397         // Place FPGA in passthrough mode, in this mode the CROSS_LO line
 398         // connects to SSP_DIN and the SSP_DOUT logic level controls
 399         // whether we're modulating the antenna (high)
 400         // or listening to the antenna (low)
 401         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
 402         LED_A_ON();
 403
 404         // steal this pin from the SSP and use it to control the modulation
 405         AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
 406         AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
 407
 408         // writing algorithm:
 409         // a high bit consists of a field off for 1ms and field on for 1ms
 410         // a low bit consists of a field off for 0.3ms and field on for 1.7ms
 411         // initiate a charge time of 50ms (field on) then immediately start writing bits
 412         // start by writing 0xBB (keyword) and 0xEB (password)
 413         // then write 80 bits of data (or 64 bit data + 16 bit crc if you prefer)
 414         // finally end with 0x0300 (write frame)
 415         // all data is sent lsb firts
 416         // finish with 15ms programming time
 417
 418         // modulate antenna
 419         HIGH(GPIO_SSC_DOUT);
 420         SpinDelay(50);  // charge time
 421
 422         WriteTIbyte(0xbb); // keyword
 423         WriteTIbyte(0xeb); // password
 424         WriteTIbyte( (idlo    )&0xff );
 425         WriteTIbyte( (idlo>>8 )&0xff );
 426         WriteTIbyte( (idlo>>16)&0xff );
 427         WriteTIbyte( (idlo>>24)&0xff );
 428         WriteTIbyte( (idhi    )&0xff );
 429         WriteTIbyte( (idhi>>8 )&0xff );
 430         WriteTIbyte( (idhi>>16)&0xff );
 431         WriteTIbyte( (idhi>>24)&0xff ); // data hi to lo
 432         WriteTIbyte( (crc     )&0xff ); // crc lo
 433         WriteTIbyte( (crc>>8  )&0xff ); // crc hi
 434         WriteTIbyte(0x00); // write frame lo
 435         WriteTIbyte(0x03); // write frame hi
 436         HIGH(GPIO_SSC_DOUT);
 437         SpinDelay(50);  // programming time
 438
 439         LED_A_OFF();
 440
 441         // get TI tag data into the buffer
 442         AcquireTiType();
 443
 444         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 445         DbpString("Now use tiread to check");
 446 }
 447
 448 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 449 {
 450         int i;
 451         uint8_t *tab = (uint8_t *)BigBuf;
 452
 453         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 454         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
 455
 456         AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
 457
 458         AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
 459         AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
 460
 461 #define SHORT_COIL()    LOW(GPIO_SSC_DOUT)
 462 #define OPEN_COIL()             HIGH(GPIO_SSC_DOUT)
 463
 464         i = 0;
 465         for(;;) {
 466                 while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
 467                         if(BUTTON_PRESS()) {
 468                                 DbpString("Stopped");
 469                                 return;
 470                         }
 471                         WDT_HIT();
 472                 }
 473
 474                 if (ledcontrol)
 475                         LED_D_ON();
 476
 477                 if(tab[i])
 478                         OPEN_COIL();
 479                 else
 480                         SHORT_COIL();
 481
 482                 if (ledcontrol)
 483                         LED_D_OFF();
 484
 485                 while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
 486                         if(BUTTON_PRESS()) {
 487                                 DbpString("Stopped");
 488                                 return;
 489                         }
 490                         WDT_HIT();
 491                 }
 492
 493                 i++;
 494                 if(i == period) {
 495                         i = 0;
 496                         if (gap) {
 497                                 SHORT_COIL();
 498                                 SpinDelayUs(gap);
 499                         }
 500                 }
 501         }
 502 }
 503
 504 #define DEBUG_FRAME_CONTENTS 1
 505 void SimulateTagLowFrequencyBidir(int divisor, int t0)
 506 {
 507 }
 508
 509 // compose fc/8 fc/10 waveform
 510 static void fc(int c, int *n) {
 511         uint8_t *dest = (uint8_t *)BigBuf;
 512         int idx;
 513
 514         // for when we want an fc8 pattern every 4 logical bits
 515         if(c==0) {
 516                 dest[((*n)++)]=1;
 517                 dest[((*n)++)]=1;
 518                 dest[((*n)++)]=0;
 519                 dest[((*n)++)]=0;
 520                 dest[((*n)++)]=0;
 521                 dest[((*n)++)]=0;
 522                 dest[((*n)++)]=0;
 523                 dest[((*n)++)]=0;
 524         }
 525         //      an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples
 526         if(c==8) {
 527                 for (idx=0; idx<6; idx++) {
 528                         dest[((*n)++)]=1;
 529                         dest[((*n)++)]=1;
 530                         dest[((*n)++)]=0;
 531                         dest[((*n)++)]=0;
 532                         dest[((*n)++)]=0;
 533                         dest[((*n)++)]=0;
 534                         dest[((*n)++)]=0;
 535                         dest[((*n)++)]=0;
 536                 }
 537         }
 538
 539         //      an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
 540         if(c==10) {
 541                 for (idx=0; idx<5; idx++) {
 542                         dest[((*n)++)]=1;
 543                         dest[((*n)++)]=1;
 544                         dest[((*n)++)]=1;
 545                         dest[((*n)++)]=0;
 546                         dest[((*n)++)]=0;
 547                         dest[((*n)++)]=0;
 548                         dest[((*n)++)]=0;
 549                         dest[((*n)++)]=0;
 550                         dest[((*n)++)]=0;
 551                         dest[((*n)++)]=0;
 552                 }
 553         }
 554 }
 555
 556 // prepare a waveform pattern in the buffer based on the ID given then
 557 // simulate a HID tag until the button is pressed
 558 void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
 559 {
 560         int n=0, i=0;
 561         /*
 562          HID tag bitstream format
 563          The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
 564          A 1 bit is represented as 6 fc8 and 5 fc10 patterns
 565          A 0 bit is represented as 5 fc10 and 6 fc8 patterns
 566          A fc8 is inserted before every 4 bits
 567          A special start of frame pattern is used consisting a0b0 where a and b are neither 0
 568          nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
 569         */
 570
 571         if (hi>0xFFF) {
 572                 DbpString("Tags can only have 44 bits.");
 573                 return;
 574         }
 575         fc(0,&n);
 576         // special start of frame marker containing invalid bit sequences
 577         fc(8,  &n);     fc(8,  &n);     // invalid
 578         fc(8,  &n);     fc(10, &n); // logical 0
 579         fc(10, &n);     fc(10, &n); // invalid
 580         fc(8,  &n);     fc(10, &n); // logical 0
 581
 582         WDT_HIT();
 583         // manchester encode bits 43 to 32
 584         for (i=11; i>=0; i--) {
 585                 if ((i%4)==3) fc(0,&n);
 586                 if ((hi>>i)&1) {
 587                         fc(10, &n);     fc(8,  &n);             // low-high transition
 588                 } else {
 589                         fc(8,  &n);     fc(10, &n);             // high-low transition
 590                 }
 591         }
 592
 593         WDT_HIT();
 594         // manchester encode bits 31 to 0
 595         for (i=31; i>=0; i--) {
 596                 if ((i%4)==3) fc(0,&n);
 597                 if ((lo>>i)&1) {
 598                         fc(10, &n);     fc(8,  &n);             // low-high transition
 599                 } else {
 600                         fc(8,  &n);     fc(10, &n);             // high-low transition
 601                 }
 602         }
 603
 604         if (ledcontrol)
 605                 LED_A_ON();
 606         SimulateTagLowFrequency(n, 0, ledcontrol);
 607
 608         if (ledcontrol)
 609                 LED_A_OFF();
 610 }
 611
 612
 613 // loop to capture raw HID waveform then FSK demodulate the TAG ID from it
 614 void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
 615 {
 616         uint8_t *dest = (uint8_t *)BigBuf;
 617         int m=0, n=0, i=0, idx=0, found=0, lastval=0;
 618   uint32_t hi2=0, hi=0, lo=0;
 619
 620         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 621         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 622         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 623
 624         // Connect the A/D to the peak-detected low-frequency path.
 625         SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
 626
 627         // Give it a bit of time for the resonant antenna to settle.
 628         SpinDelay(50);
 629
 630         // Now set up the SSC to get the ADC samples that are now streaming at us.
 631         FpgaSetupSsc();
 632
 633         for(;;) {
 634                 WDT_HIT();
 635                 if (ledcontrol)
 636                         LED_A_ON();
 637                 if(BUTTON_PRESS()) {
 638                         DbpString("Stopped");
 639                         if (ledcontrol)
 640                                 LED_A_OFF();
 641                         return;
 642                 }
 643
 644                 i = 0;
 645                 m = sizeof(BigBuf);
 646                 memset(dest,128,m);
 647                 for(;;) {
 648                         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
 649                                 AT91C_BASE_SSC->SSC_THR = 0x43;
 650                                 if (ledcontrol)
 651                                         LED_D_ON();
 652                         }
 653                         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 654                                 dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 655                                 // we don't care about actual value, only if it's more or less than a
 656                                 // threshold essentially we capture zero crossings for later analysis
 657                                 if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
 658                                 i++;
 659                                 if (ledcontrol)
 660                                         LED_D_OFF();
 661                                 if(i >= m) {
 662                                         break;
 663                                 }
 664                         }
 665                 }
 666
 667                 // FSK demodulator
 668
 669                 // sync to first lo-hi transition
 670                 for( idx=1; idx<m; idx++) {
 671                         if (dest[idx-1]<dest[idx])
 672                                 lastval=idx;
 673                                 break;
 674                 }
 675                 WDT_HIT();
 676
 677                 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
 678                 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
 679                 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
 680                 for( i=0; idx<m; idx++) {
 681                         if (dest[idx-1]<dest[idx]) {
 682                                 dest[i]=idx-lastval;
 683                                 if (dest[i] <= 8) {
 684                                                 dest[i]=1;
 685                                 } else {
 686                                                 dest[i]=0;
 687                                 }
 688
 689                                 lastval=idx;
 690                                 i++;
 691                         }
 692                 }
 693                 m=i;
 694                 WDT_HIT();
 695
 696                 // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
 697                 lastval=dest[0];
 698                 idx=0;
 699                 i=0;
 700                 n=0;
 701                 for( idx=0; idx<m; idx++) {
 702                         if (dest[idx]==lastval) {
 703                                 n++;
 704                         } else {
 705                                 // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
 706                                 // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
 707                                 // swallowed up by rounding
 708                                 // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
 709                                 // special start of frame markers use invalid manchester states (no transitions) by using sequences
 710                                 // like 111000
 711                                 if (dest[idx-1]) {
 712                                         n=(n+1)/6;                      // fc/8 in sets of 6
 713                                 } else {
 714                                         n=(n+1)/5;                      // fc/10 in sets of 5
 715                                 }
 716                                 switch (n) {                    // stuff appropriate bits in buffer
 717                                         case 0:
 718                                         case 1: // one bit
 719                                                 dest[i++]=dest[idx-1];
 720                                                 break;
 721                                         case 2: // two bits
 722                                                 dest[i++]=dest[idx-1];
 723                                                 dest[i++]=dest[idx-1];
 724                                                 break;
 725                                         case 3: // 3 bit start of frame markers
 726                                                 dest[i++]=dest[idx-1];
 727                                                 dest[i++]=dest[idx-1];
 728                                                 dest[i++]=dest[idx-1];
 729                                                 break;
 730                                         // When a logic 0 is immediately followed by the start of the next transmisson
 731                                         // (special pattern) a pattern of 4 bit duration lengths is created.
 732                                         case 4:
 733                                                 dest[i++]=dest[idx-1];
 734                                                 dest[i++]=dest[idx-1];
 735                                                 dest[i++]=dest[idx-1];
 736                                                 dest[i++]=dest[idx-1];
 737                                                 break;
 738                                         default:        // this shouldn't happen, don't stuff any bits
 739                                                 break;
 740                                 }
 741                                 n=0;
 742                                 lastval=dest[idx];
 743                         }
 744                 }
 745                 m=i;
 746                 WDT_HIT();
 747
 748                 // final loop, go over previously decoded manchester data and decode into usable tag ID
 749                 // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
 750                 for( idx=0; idx<m-6; idx++) {
 751                         // search for a start of frame marker
 752                         if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
 753                         {
 754                                 found=1;
 755                                 idx+=6;
 756         if (found && (hi2|hi|lo)) {
 757           if (hi2 != 0){
 758             Dbprintf("TAG ID: %x%08x%08x (%d)",
 759                      (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
 760           }
 761           else {
 762             Dbprintf("TAG ID: %x%08x (%d)",
 763                      (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
 764           }
 765                                         /* if we're only looking for one tag */
 766                                         if (findone)
 767                                         {
 768                                                 *high = hi;
 769                                                 *low = lo;
 770                                                 return;
 771                                         }
 772           hi2=0;
 773                                         hi=0;
 774                                         lo=0;
 775                                         found=0;
 776                                 }
 777                         }
 778                         if (found) {
 779                                 if (dest[idx] && (!dest[idx+1]) ) {
 780           hi2=(hi2<<1)|(hi>>31);
 781                                         hi=(hi<<1)|(lo>>31);
 782                                         lo=(lo<<1)|0;
 783                                 } else if ( (!dest[idx]) && dest[idx+1]) {
 784           hi2=(hi2<<1)|(hi>>31);
 785                                         hi=(hi<<1)|(lo>>31);
 786                                         lo=(lo<<1)|1;
 787                                 } else {
 788                                         found=0;
 789           hi2=0;
 790                                         hi=0;
 791                                         lo=0;
 792                                 }
 793                                 idx++;
 794                         }
 795                         if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
 796                         {
 797                                 found=1;
 798                                 idx+=6;
 799                                 if (found && (hi|lo)) {
 800           if (hi2 != 0){
 801             Dbprintf("TAG ID: %x%08x%08x (%d)",
 802                      (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
 803           }
 804           else {
 805             Dbprintf("TAG ID: %x%08x (%d)",
 806                      (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
 807           }
 808                                         /* if we're only looking for one tag */
 809                                         if (findone)
 810                                         {
 811                                                 *high = hi;
 812                                                 *low = lo;
 813                                                 return;
 814                                         }
 815           hi2=0;
 816                                         hi=0;
 817                                         lo=0;
 818                                         found=0;
 819                                 }
 820                         }
 821                 }
 822                 WDT_HIT();
 823         }
 824 }
 825
 826 void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
 827 {
 828         uint8_t *dest = (uint8_t *)BigBuf;
 829         int m=0, n=0, i=0, idx=0, lastval=0;
 830         int found=0;
 831         uint32_t code=0, code2=0;
 832         //uint32_t hi2=0, hi=0, lo=0;
 833
 834         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 835         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 836         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 837
 838         // Connect the A/D to the peak-detected low-frequency path.
 839         SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
 840
 841         // Give it a bit of time for the resonant antenna to settle.
 842         SpinDelay(50);
 843
 844         // Now set up the SSC to get the ADC samples that are now streaming at us.
 845         FpgaSetupSsc();
 846
 847         for(;;) {
 848                 WDT_HIT();
 849                 if (ledcontrol)
 850                         LED_A_ON();
 851                 if(BUTTON_PRESS()) {
 852                         DbpString("Stopped");
 853                         if (ledcontrol)
 854                                 LED_A_OFF();
 855                         return;
 856                 }
 857
 858                 i = 0;
 859                 m = sizeof(BigBuf);
 860                 memset(dest,128,m);
 861                 for(;;) {
 862                         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
 863                                 AT91C_BASE_SSC->SSC_THR = 0x43;
 864                                 if (ledcontrol)
 865                                         LED_D_ON();
 866                         }
 867                         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 868                                 dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 869                                 // we don't care about actual value, only if it's more or less than a
 870                                 // threshold essentially we capture zero crossings for later analysis
 871                                 if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
 872                                 i++;
 873                                 if (ledcontrol)
 874                                         LED_D_OFF();
 875                                 if(i >= m) {
 876                                         break;
 877                                 }
 878                         }
 879                 }
 880
 881                 // FSK demodulator
 882
 883                 // sync to first lo-hi transition
 884                 for( idx=1; idx<m; idx++) {
 885                         if (dest[idx-1]<dest[idx])
 886                                 lastval=idx;
 887                                 break;
 888                 }
 889                 WDT_HIT();
 890
 891                 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
 892                 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
 893                 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
 894                 for( i=0; idx<m; idx++) {
 895                         if (dest[idx-1]<dest[idx]) {
 896                                 dest[i]=idx-lastval;
 897                                 if (dest[i] <= 8) {
 898                                                 dest[i]=1;
 899                                 } else {
 900                                                 dest[i]=0;
 901                                 }
 902
 903                                 lastval=idx;
 904                                 i++;
 905                         }
 906                 }
 907                 m=i;
 908                 WDT_HIT();
 909
 910                 // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
 911                 lastval=dest[0];
 912                 idx=0;
 913                 i=0;
 914                 n=0;
 915                 for( idx=0; idx<m; idx++) {
 916                         if (dest[idx]==lastval) {
 917                                 n++;
 918                         } else {
 919                                 // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
 920                                 // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
 921                                 // swallowed up by rounding
 922                                 // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
 923                                 // special start of frame markers use invalid manchester states (no transitions) by using sequences
 924                                 // like 111000
 925                                 if (dest[idx-1]) {
 926                                         n=(n+1)/7;                      // fc/8 in sets of 7
 927                                 } else {
 928                                         n=(n+1)/6;                      // fc/10 in sets of 6
 929                                 }
 930                                 switch (n) {                    // stuff appropriate bits in buffer
 931                                         case 0:
 932                                         case 1: // one bit
 933                                                 dest[i++]=dest[idx-1]^1;
 934                                                 //Dbprintf("%d",dest[idx-1]);
 935                                                 break;
 936                                         case 2: // two bits
 937                                                 dest[i++]=dest[idx-1]^1;
 938                                                 dest[i++]=dest[idx-1]^1;
 939                                                 //Dbprintf("%d",dest[idx-1]);
 940                                                 //Dbprintf("%d",dest[idx-1]);
 941                                                 break;
 942                                         case 3: // 3 bit start of frame markers
 943                                                 for(int j=0; j<3; j++){
 944                                                   dest[i++]=dest[idx-1]^1;
 945                                                 //  Dbprintf("%d",dest[idx-1]);
 946                                                 }
 947                                                 break;
 948                                         case 4:
 949                                                 for(int j=0; j<4; j++){
 950                                                   dest[i++]=dest[idx-1]^1;
 951                                                 //  Dbprintf("%d",dest[idx-1]);
 952                                                 }
 953                                                 break;
 954                                         case 5:
 955                                                 for(int j=0; j<5; j++){
 956                                                   dest[i++]=dest[idx-1]^1;
 957                                                 //  Dbprintf("%d",dest[idx-1]);
 958                                                 }
 959                                                 break;
 960                                         case 6:
 961                                                 for(int j=0; j<6; j++){
 962                                                   dest[i++]=dest[idx-1]^1;
 963                                                 //  Dbprintf("%d",dest[idx-1]);
 964                                                 }
 965                                                 break;
 966                                         case 7:
 967                                                 for(int j=0; j<7; j++){
 968                                                   dest[i++]=dest[idx-1]^1;
 969                                                 //  Dbprintf("%d",dest[idx-1]);
 970                                                 }
 971                                                 break;
 972                                         case 8:
 973                                                 for(int j=0; j<8; j++){
 974                                                   dest[i++]=dest[idx-1]^1;
 975                                                 //  Dbprintf("%d",dest[idx-1]);
 976                                                 }
 977                                                 break;
 978                                         case 9:
 979                                                 for(int j=0; j<9; j++){
 980                                                   dest[i++]=dest[idx-1]^1;
 981                                                 //  Dbprintf("%d",dest[idx-1]);
 982                                                 }
 983                                                 break;
 984                                         case 10:
 985                                                 for(int j=0; j<10; j++){
 986                                                   dest[i++]=dest[idx-1]^1;
 987                                                 //  Dbprintf("%d",dest[idx-1]);
 988                                                 }
 989                                                 break;
 990                                         case 11:
 991                                                 for(int j=0; j<11; j++){
 992                                                   dest[i++]=dest[idx-1]^1;
 993                                                 //  Dbprintf("%d",dest[idx-1]);
 994                                                 }
 995                                                 break;
 996                                         case 12:
 997                                                 for(int j=0; j<12; j++){
 998                                                   dest[i++]=dest[idx-1]^1;
 999                                                  // Dbprintf("%d",dest[idx-1]);
1000                                                 }
1001                                                 break;
1002                                         default:        // this shouldn't happen, don't stuff any bits
1003                                                 //Dbprintf("%d",dest[idx-1]);
1004                                                 break;
1005                                 }
1006                                 n=0;
1007                                 lastval=dest[idx];
1008                         }
1009                 }//end for
1010                 /*for(int j=0; j<64;j+=8){
1011                   Dbprintf("%d%d%d%d%d%d%d%d",dest[j],dest[j+1],dest[j+2],dest[j+3],dest[j+4],dest[j+5],dest[j+6],dest[j+7]);
1012                 }
1013                 Dbprintf("\n");*/
1014                 m=i;
1015                 WDT_HIT();
1016
1017         for( idx=0; idx<m-9; idx++) {
1018           if ( !(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])&& (dest[idx+9])){
1019                 found=1;
1020                 //idx+=9;
1021                 if (found) {
1022                     Dbprintf("%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]);
1023                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+8], dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15]);
1024                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+16],dest[idx+17],dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23]);
1025                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+24],dest[idx+25],dest[idx+26],dest[idx+27],dest[idx+28],dest[idx+29],dest[idx+30],dest[idx+31]);
1026                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+32],dest[idx+33],dest[idx+34],dest[idx+35],dest[idx+36],dest[idx+37],dest[idx+38],dest[idx+39]);
1027                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44],dest[idx+45],dest[idx+46],dest[idx+47]);
1028                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53],dest[idx+54],dest[idx+55]);
1029                     Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
1030
1031                     short version='\x00';
1032                     char unknown='\x00';
1033                     uint16_t number=0;
1034                     for(int j=14;j<18;j++){
1035                        //Dbprintf("%d",dest[idx+j]);
1036                        version <<=1;
1037                        if (dest[idx+j]) version |= 1;
1038                     }
1039                     for(int j=19;j<27;j++){
1040                        //Dbprintf("%d",dest[idx+j]);
1041                        unknown <<=1;
1042                        if (dest[idx+j]) unknown |= 1;
1043                     }
1044                     for(int j=36;j<45;j++){
1045                        //Dbprintf("%d",dest[idx+j]);
1046                        number <<=1;
1047                        if (dest[idx+j]) number |= 1;
1048                     }
1049                     for(int j=46;j<53;j++){
1050                        //Dbprintf("%d",dest[idx+j]);
1051                        number <<=1;
1052                        if (dest[idx+j]) number |= 1;
1053                     }
1054                     for(int j=0; j<32; j++){
1055                         code <<=1;
1056                         if(dest[idx+j]) code |= 1;
1057                     }
1058                     for(int j=32; j<64; j++){
1059                         code2 <<=1;
1060                         if(dest[idx+j]) code2 |= 1;
1061                     }
1062
1063                     Dbprintf("XSF(%02d)%02x:%d (%08x%08x)",version,unknown,number,code,code2);
1064                     if (ledcontrol)
1065                         LED_D_OFF();
1066                 }
1067                 // if we're only looking for one tag
1068                 if (findone){
1069                         //*high = hi;
1070                         //*low = lo;
1071                         LED_A_OFF();
1072                         return;
1073                 }
1074
1075                 //hi=0;
1076                 //lo=0;
1077                 found=0;
1078           }
1079
1080         }
1081         }
1082         WDT_HIT();
1083 }
1084
1085 /*------------------------------
1086  * T5555/T5557/T5567 routines
1087  *------------------------------
1088  */
1089
1090 /* T55x7 configuration register definitions */
1091 #define T55x7_POR_DELAY                 0x00000001
1092 #define T55x7_ST_TERMINATOR             0x00000008
1093 #define T55x7_PWD                       0x00000010
1094 #define T55x7_MAXBLOCK_SHIFT            5
1095 #define T55x7_AOR                       0x00000200
1096 #define T55x7_PSKCF_RF_2                0
1097 #define T55x7_PSKCF_RF_4                0x00000400
1098 #define T55x7_PSKCF_RF_8                0x00000800
1099 #define T55x7_MODULATION_DIRECT         0
1100 #define T55x7_MODULATION_PSK1           0x00001000
1101 #define T55x7_MODULATION_PSK2           0x00002000
1102 #define T55x7_MODULATION_PSK3           0x00003000
1103 #define T55x7_MODULATION_FSK1           0x00004000
1104 #define T55x7_MODULATION_FSK2           0x00005000
1105 #define T55x7_MODULATION_FSK1a          0x00006000
1106 #define T55x7_MODULATION_FSK2a          0x00007000
1107 #define T55x7_MODULATION_MANCHESTER     0x00008000
1108 #define T55x7_MODULATION_BIPHASE        0x00010000
1109 #define T55x7_BITRATE_RF_8              0
1110 #define T55x7_BITRATE_RF_16             0x00040000
1111 #define T55x7_BITRATE_RF_32             0x00080000
1112 #define T55x7_BITRATE_RF_40             0x000C0000
1113 #define T55x7_BITRATE_RF_50             0x00100000
1114 #define T55x7_BITRATE_RF_64             0x00140000
1115 #define T55x7_BITRATE_RF_100            0x00180000
1116 #define T55x7_BITRATE_RF_128            0x001C0000
1117
1118 /* T5555 (Q5) configuration register definitions */
1119 #define T5555_ST_TERMINATOR             0x00000001
1120 #define T5555_MAXBLOCK_SHIFT            0x00000001
1121 #define T5555_MODULATION_MANCHESTER     0
1122 #define T5555_MODULATION_PSK1           0x00000010
1123 #define T5555_MODULATION_PSK2           0x00000020
1124 #define T5555_MODULATION_PSK3           0x00000030
1125 #define T5555_MODULATION_FSK1           0x00000040
1126 #define T5555_MODULATION_FSK2           0x00000050
1127 #define T5555_MODULATION_BIPHASE        0x00000060
1128 #define T5555_MODULATION_DIRECT         0x00000070
1129 #define T5555_INVERT_OUTPUT             0x00000080
1130 #define T5555_PSK_RF_2                  0
1131 #define T5555_PSK_RF_4                  0x00000100
1132 #define T5555_PSK_RF_8                  0x00000200
1133 #define T5555_USE_PWD                   0x00000400
1134 #define T5555_USE_AOR                   0x00000800
1135 #define T5555_BITRATE_SHIFT             12
1136 #define T5555_FAST_WRITE                0x00004000
1137 #define T5555_PAGE_SELECT               0x00008000
1138
1139 /*
1140  * Relevant times in microsecond
1141  * To compensate antenna falling times shorten the write times
1142  * and enlarge the gap ones.
1143  */
1144 #define START_GAP 250
1145 #define WRITE_GAP 160
1146 #define WRITE_0   144 // 192
1147 #define WRITE_1   400 // 432 for T55x7; 448 for E5550
1148
1149 // Write one bit to card
1150 void T55xxWriteBit(int bit)
1151 {
1152         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
1153         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1154         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1155         if (bit == 0)
1156                 SpinDelayUs(WRITE_0);
1157         else
1158                 SpinDelayUs(WRITE_1);
1159         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1160         SpinDelayUs(WRITE_GAP);
1161 }
1162
1163 // Write one card block in page 0, no lock
1164 void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t PwdMode)
1165 {
1166         unsigned int i;
1167
1168         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
1169         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1170         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1171
1172         // Give it a bit of time for the resonant antenna to settle.
1173         // And for the tag to fully power up
1174         SpinDelay(150);
1175
1176         // Now start writting
1177         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1178         SpinDelayUs(START_GAP);
1179
1180         // Opcode
1181         T55xxWriteBit(1);
1182         T55xxWriteBit(0); //Page 0
1183   if (PwdMode == 1){
1184     // Pwd
1185     for (i = 0x80000000; i != 0; i >>= 1)
1186       T55xxWriteBit(Pwd & i);
1187   }
1188         // Lock bit
1189         T55xxWriteBit(0);
1190
1191         // Data
1192         for (i = 0x80000000; i != 0; i >>= 1)
1193                 T55xxWriteBit(Data & i);
1194
1195         // Block
1196         for (i = 0x04; i != 0; i >>= 1)
1197                 T55xxWriteBit(Block & i);
1198
1199         // Now perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
1200         // so wait a little more)
1201         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1202         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1203         SpinDelay(20);
1204         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1205 }
1206
1207 // Read one card block in page 0
1208 void T55xxReadBlock(uint32_t Block, uint32_t Pwd, uint8_t PwdMode)
1209 {
1210         uint8_t *dest = (uint8_t *)BigBuf;
1211         int m=0, i=0;
1212
1213         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
1214         m = sizeof(BigBuf);
1215   // Clear destination buffer before sending the command
1216         memset(dest, 128, m);
1217         // Connect the A/D to the peak-detected low-frequency path.
1218         SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
1219         // Now set up the SSC to get the ADC samples that are now streaming at us.
1220         FpgaSetupSsc();
1221
1222         LED_D_ON();
1223         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1224         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1225
1226         // Give it a bit of time for the resonant antenna to settle.
1227         // And for the tag to fully power up
1228         SpinDelay(150);
1229
1230         // Now start writting
1231         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1232         SpinDelayUs(START_GAP);
1233
1234         // Opcode
1235         T55xxWriteBit(1);
1236         T55xxWriteBit(0); //Page 0
1237         if (PwdMode == 1){
1238                 // Pwd
1239                 for (i = 0x80000000; i != 0; i >>= 1)
1240                         T55xxWriteBit(Pwd & i);
1241         }
1242         // Lock bit
1243         T55xxWriteBit(0);
1244         // Block
1245         for (i = 0x04; i != 0; i >>= 1)
1246                 T55xxWriteBit(Block & i);
1247
1248   // Turn field on to read the response
1249         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1250         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1251
1252         // Now do the acquisition
1253         i = 0;
1254         for(;;) {
1255                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
1256                         AT91C_BASE_SSC->SSC_THR = 0x43;
1257                 }
1258                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
1259                         dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1260                         // we don't care about actual value, only if it's more or less than a
1261                         // threshold essentially we capture zero crossings for later analysis
1262       //                        if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
1263                         i++;
1264                         if (i >= m) break;
1265                 }
1266         }
1267
1268   FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
1269         LED_D_OFF();
1270         DbpString("DONE!");
1271 }
1272
1273 // Read card traceability data (page 1)
1274 void T55xxReadTrace(void){
1275         uint8_t *dest = (uint8_t *)BigBuf;
1276         int m=0, i=0;
1277
1278         FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
1279         m = sizeof(BigBuf);
1280   // Clear destination buffer before sending the command
1281         memset(dest, 128, m);
1282         // Connect the A/D to the peak-detected low-frequency path.
1283         SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
1284         // Now set up the SSC to get the ADC samples that are now streaming at us.
1285         FpgaSetupSsc();
1286
1287         LED_D_ON();
1288         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1289         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1290
1291         // Give it a bit of time for the resonant antenna to settle.
1292         // And for the tag to fully power up
1293         SpinDelay(150);
1294
1295         // Now start writting
1296         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1297         SpinDelayUs(START_GAP);
1298
1299         // Opcode
1300         T55xxWriteBit(1);
1301         T55xxWriteBit(1); //Page 1
1302
1303   // Turn field on to read the response
1304         FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1305         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1306
1307         // Now do the acquisition
1308         i = 0;
1309         for(;;) {
1310                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
1311                         AT91C_BASE_SSC->SSC_THR = 0x43;
1312                 }
1313                 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
1314                         dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1315                         i++;
1316                         if (i >= m) break;
1317                 }
1318         }
1319
1320   FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
1321         LED_D_OFF();
1322         DbpString("DONE!");
1323 }
1324
1325 /*-------------- Cloning routines -----------*/
1326 // Copy HID id to card and setup block 0 config
1327 void CopyHIDtoT55x7(uint32_t hi2, uint32_t hi, uint32_t lo, uint8_t longFMT)
1328 {
1329         int data1=0, data2=0, data3=0, data4=0, data5=0, data6=0; //up to six blocks for long format
1330         int last_block = 0;
1331
1332   if (longFMT){
1333           // Ensure no more than 84 bits supplied
1334           if (hi2>0xFFFFF) {
1335                   DbpString("Tags can only have 84 bits.");
1336                   return;
1337           }
1338     // Build the 6 data blocks for supplied 84bit ID
1339     last_block = 6;
1340     data1 = 0x1D96A900; // load preamble (1D) & long format identifier (9E manchester encoded)
1341           for (int i=0;i<4;i++) {
1342                   if (hi2 & (1<<(19-i)))
1343                           data1 |= (1<<(((3-i)*2)+1)); // 1 -> 10
1344                   else
1345                           data1 |= (1<<((3-i)*2)); // 0 -> 01
1346           }
1347
1348         data2 = 0;
1349         for (int i=0;i<16;i++) {
1350                 if (hi2 & (1<<(15-i)))
1351                         data2 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1352                 else
1353                         data2 |= (1<<((15-i)*2)); // 0 -> 01
1354     }
1355
1356         data3 = 0;
1357         for (int i=0;i<16;i++) {
1358                 if (hi & (1<<(31-i)))
1359                         data3 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1360                 else
1361                         data3 |= (1<<((15-i)*2)); // 0 -> 01
1362         }
1363
1364         data4 = 0;
1365         for (int i=0;i<16;i++) {
1366                 if (hi & (1<<(15-i)))
1367                         data4 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1368                 else
1369                         data4 |= (1<<((15-i)*2)); // 0 -> 01
1370     }
1371
1372         data5 = 0;
1373         for (int i=0;i<16;i++) {
1374                 if (lo & (1<<(31-i)))
1375                         data5 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1376                 else
1377                         data5 |= (1<<((15-i)*2)); // 0 -> 01
1378         }
1379
1380         data6 = 0;
1381         for (int i=0;i<16;i++) {
1382                 if (lo & (1<<(15-i)))
1383                         data6 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1384                 else
1385                         data6 |= (1<<((15-i)*2)); // 0 -> 01
1386     }
1387   }
1388   else {
1389           // Ensure no more than 44 bits supplied
1390           if (hi>0xFFF) {
1391                   DbpString("Tags can only have 44 bits.");
1392                   return;
1393           }
1394
1395         // Build the 3 data blocks for supplied 44bit ID
1396         last_block = 3;
1397
1398         data1 = 0x1D000000; // load preamble
1399
1400     for (int i=0;i<12;i++) {
1401       if (hi & (1<<(11-i)))
1402         data1 |= (1<<(((11-i)*2)+1)); // 1 -> 10
1403       else
1404         data1 |= (1<<((11-i)*2)); // 0 -> 01
1405     }
1406
1407         data2 = 0;
1408         for (int i=0;i<16;i++) {
1409                 if (lo & (1<<(31-i)))
1410                         data2 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1411                 else
1412                         data2 |= (1<<((15-i)*2)); // 0 -> 01
1413         }
1414
1415         data3 = 0;
1416         for (int i=0;i<16;i++) {
1417                 if (lo & (1<<(15-i)))
1418                         data3 |= (1<<(((15-i)*2)+1)); // 1 -> 10
1419                 else
1420                         data3 |= (1<<((15-i)*2)); // 0 -> 01
1421         }
1422   }
1423
1424         LED_D_ON();
1425         // Program the data blocks for supplied ID
1426         // and the block 0 for HID format
1427         T55xxWriteBlock(data1,1,0,0);
1428         T55xxWriteBlock(data2,2,0,0);
1429         T55xxWriteBlock(data3,3,0,0);
1430
1431         if (longFMT) { // if long format there are 6 blocks
1432           T55xxWriteBlock(data4,4,0,0);
1433           T55xxWriteBlock(data5,5,0,0);
1434           T55xxWriteBlock(data6,6,0,0);
1435   }
1436
1437         // Config for HID (RF/50, FSK2a, Maxblock=3 for short/6 for long)
1438         T55xxWriteBlock(T55x7_BITRATE_RF_50    |
1439                   T55x7_MODULATION_FSK2a |
1440                   last_block << T55x7_MAXBLOCK_SHIFT,
1441                   0,0,0);
1442
1443         LED_D_OFF();
1444
1445         DbpString("DONE!");
1446 }
1447
1448 void CopyIOtoT55x7(uint32_t hi, uint32_t lo, uint8_t longFMT)
1449 {
1450    int data1=0, data2=0; //up to six blocks for long format
1451
1452     data1 = hi;  // load preamble
1453     data2 = lo;
1454
1455     LED_D_ON();
1456     // Program the data blocks for supplied ID
1457     // and the block 0 for HID format
1458     T55xxWriteBlock(data1,1,0,0);
1459     T55xxWriteBlock(data2,2,0,0);
1460
1461     //Config Block
1462     T55xxWriteBlock(0x00147040,0,0,0);
1463     LED_D_OFF();
1464
1465     DbpString("DONE!");
1466 }
1467
1468 // Define 9bit header for EM410x tags
1469 #define EM410X_HEADER           0x1FF
1470 #define EM410X_ID_LENGTH        40
1471
1472 void WriteEM410x(uint32_t card, uint32_t id_hi, uint32_t id_lo)
1473 {
1474         int i, id_bit;
1475         uint64_t id = EM410X_HEADER;
1476         uint64_t rev_id = 0;    // reversed ID
1477         int c_parity[4];        // column parity
1478         int r_parity = 0;       // row parity
1479         uint32_t clock = 0;
1480
1481         // Reverse ID bits given as parameter (for simpler operations)
1482         for (i = 0; i < EM410X_ID_LENGTH; ++i) {
1483                 if (i < 32) {
1484                         rev_id = (rev_id << 1) | (id_lo & 1);
1485                         id_lo >>= 1;
1486                 } else {
1487                         rev_id = (rev_id << 1) | (id_hi & 1);
1488                         id_hi >>= 1;
1489                 }
1490         }
1491
1492         for (i = 0; i < EM410X_ID_LENGTH; ++i) {
1493                 id_bit = rev_id & 1;
1494
1495                 if (i % 4 == 0) {
1496                         // Don't write row parity bit at start of parsing
1497                         if (i)
1498                                 id = (id << 1) | r_parity;
1499                         // Start counting parity for new row
1500                         r_parity = id_bit;
1501                 } else {
1502                         // Count row parity
1503                         r_parity ^= id_bit;
1504                 }
1505
1506                 // First elements in column?
1507                 if (i < 4)
1508                         // Fill out first elements
1509                         c_parity[i] = id_bit;
1510                 else
1511                         // Count column parity
1512                         c_parity[i % 4] ^= id_bit;
1513
1514                 // Insert ID bit
1515                 id = (id << 1) | id_bit;
1516                 rev_id >>= 1;
1517         }
1518
1519         // Insert parity bit of last row
1520         id = (id << 1) | r_parity;
1521
1522         // Fill out column parity at the end of tag
1523         for (i = 0; i < 4; ++i)
1524                 id = (id << 1) | c_parity[i];
1525
1526         // Add stop bit
1527         id <<= 1;
1528
1529         Dbprintf("Started writing %s tag ...", card ? "T55x7":"T5555");
1530         LED_D_ON();
1531
1532         // Write EM410x ID
1533         T55xxWriteBlock((uint32_t)(id >> 32), 1, 0, 0);
1534         T55xxWriteBlock((uint32_t)id, 2, 0, 0);
1535
1536         // Config for EM410x (RF/64, Manchester, Maxblock=2)
1537         if (card) {
1538                 // Clock rate is stored in bits 8-15 of the card value
1539                 clock = (card & 0xFF00) >> 8;
1540                 Dbprintf("Clock rate: %d", clock);
1541                 switch (clock)
1542                 {
1543                         case 32:
1544                                 clock = T55x7_BITRATE_RF_32;
1545                                 break;
1546                         case 16:
1547                                 clock = T55x7_BITRATE_RF_16;
1548                                 break;
1549                         case 0:
1550                                 // A value of 0 is assumed to be 64 for backwards-compatibility
1551                                 // Fall through...
1552                         case 64:
1553                                 clock = T55x7_BITRATE_RF_64;
1554                                 break;
1555                         default:
1556                                 Dbprintf("Invalid clock rate: %d", clock);
1557                                 return;
1558                 }
1559
1560                 // Writing configuration for T55x7 tag
1561                 T55xxWriteBlock(clock       |
1562                                 T55x7_MODULATION_MANCHESTER |
1563                                 2 << T55x7_MAXBLOCK_SHIFT,
1564                                 0, 0, 0);
1565   }
1566         else
1567                 // Writing configuration for T5555(Q5) tag
1568                 T55xxWriteBlock(0x1F << T5555_BITRATE_SHIFT |
1569                                 T5555_MODULATION_MANCHESTER   |
1570                                 2 << T5555_MAXBLOCK_SHIFT,
1571                                 0, 0, 0);
1572
1573         LED_D_OFF();
1574         Dbprintf("Tag %s written with 0x%08x%08x\n", card ? "T55x7":"T5555",
1575                                         (uint32_t)(id >> 32), (uint32_t)id);
1576 }
1577
1578 // Clone Indala 64-bit tag by UID to T55x7
1579 void CopyIndala64toT55x7(int hi, int lo)
1580 {
1581
1582         //Program the 2 data blocks for supplied 64bit UID
1583         // and the block 0 for Indala64 format
1584         T55xxWriteBlock(hi,1,0,0);
1585         T55xxWriteBlock(lo,2,0,0);
1586         //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=2)
1587         T55xxWriteBlock(T55x7_BITRATE_RF_32    |
1588                         T55x7_MODULATION_PSK1 |
1589                         2 << T55x7_MAXBLOCK_SHIFT,
1590                         0, 0, 0);
1591         //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=2;Inverse data)
1592 //      T5567WriteBlock(0x603E1042,0);
1593
1594         DbpString("DONE!");
1595
1596 }
1597
1598 void CopyIndala224toT55x7(int uid1, int uid2, int uid3, int uid4, int uid5, int uid6, int uid7)
1599 {
1600
1601         //Program the 7 data blocks for supplied 224bit UID
1602         // and the block 0 for Indala224 format
1603         T55xxWriteBlock(uid1,1,0,0);
1604         T55xxWriteBlock(uid2,2,0,0);
1605         T55xxWriteBlock(uid3,3,0,0);
1606         T55xxWriteBlock(uid4,4,0,0);
1607         T55xxWriteBlock(uid5,5,0,0);
1608         T55xxWriteBlock(uid6,6,0,0);
1609         T55xxWriteBlock(uid7,7,0,0);
1610         //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=7)
1611         T55xxWriteBlock(T55x7_BITRATE_RF_32    |
1612                         T55x7_MODULATION_PSK1 |
1613                         7 << T55x7_MAXBLOCK_SHIFT,
1614                         0,0,0);
1615         //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=7;Inverse data)
1616 //      T5567WriteBlock(0x603E10E2,0);
1617
1618         DbpString("DONE!");
1619
1620 }
1621
1622
1623 #define abs(x) ( ((x)<0) ? -(x) : (x) )
1624 #define max(x,y) ( x<y ? y:x)
1625
1626 int DemodPCF7931(uint8_t **outBlocks) {
1627         uint8_t BitStream[256];
1628         uint8_t Blocks[8][16];
1629         uint8_t *GraphBuffer = (uint8_t *)BigBuf;
1630         int GraphTraceLen = sizeof(BigBuf);
1631         int i, j, lastval, bitidx, half_switch;
1632         int clock = 64;
1633         int tolerance = clock / 8;
1634         int pmc, block_done;
1635         int lc, warnings = 0;
1636         int num_blocks = 0;
1637         int lmin=128, lmax=128;
1638         uint8_t dir;
1639
1640         AcquireRawAdcSamples125k(0);
1641
1642         lmin = 64;
1643         lmax = 192;
1644
1645         i = 2;
1646
1647         /* Find first local max/min */
1648         if(GraphBuffer[1] > GraphBuffer[0]) {
1649     while(i < GraphTraceLen) {
1650       if( !(GraphBuffer[i] > GraphBuffer[i-1]) && GraphBuffer[i] > lmax)
1651         break;
1652       i++;
1653     }
1654     dir = 0;
1655         }
1656         else {
1657     while(i < GraphTraceLen) {
1658       if( !(GraphBuffer[i] < GraphBuffer[i-1]) && GraphBuffer[i] < lmin)
1659         break;
1660       i++;
1661     }
1662     dir = 1;
1663         }
1664
1665         lastval = i++;
1666         half_switch = 0;
1667         pmc = 0;
1668         block_done = 0;
1669
1670         for (bitidx = 0; i < GraphTraceLen; i++)
1671         {
1672     if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
1673     {
1674       lc = i - lastval;
1675       lastval = i;
1676
1677       // Switch depending on lc length:
1678       // Tolerance is 1/8 of clock rate (arbitrary)
1679       if (abs(lc-clock/4) < tolerance) {
1680         // 16T0
1681         if((i - pmc) == lc) { /* 16T0 was previous one */
1682           /* It's a PMC ! */
1683           i += (128+127+16+32+33+16)-1;
1684           lastval = i;
1685           pmc = 0;
1686           block_done = 1;
1687         }
1688         else {
1689           pmc = i;
1690         }
1691       } else if (abs(lc-clock/2) < tolerance) {
1692         // 32TO
1693         if((i - pmc) == lc) { /* 16T0 was previous one */
1694           /* It's a PMC ! */
1695           i += (128+127+16+32+33)-1;
1696           lastval = i;
1697           pmc = 0;
1698           block_done = 1;
1699         }
1700         else if(half_switch == 1) {
1701           BitStream[bitidx++] = 0;
1702           half_switch = 0;
1703         }
1704         else
1705           half_switch++;
1706       } else if (abs(lc-clock) < tolerance) {
1707         // 64TO
1708         BitStream[bitidx++] = 1;
1709       } else {
1710         // Error
1711         warnings++;
1712         if (warnings > 10)
1713         {
1714           Dbprintf("Error: too many detection errors, aborting.");
1715           return 0;
1716         }
1717       }
1718
1719       if(block_done == 1) {
1720         if(bitidx == 128) {
1721           for(j=0; j<16; j++) {
1722             Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
1723             64*BitStream[j*8+6]+
1724             32*BitStream[j*8+5]+
1725             16*BitStream[j*8+4]+
1726             8*BitStream[j*8+3]+
1727             4*BitStream[j*8+2]+
1728             2*BitStream[j*8+1]+
1729             BitStream[j*8];
1730           }
1731           num_blocks++;
1732         }
1733         bitidx = 0;
1734         block_done = 0;
1735         half_switch = 0;
1736       }
1737       if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
1738       else dir = 1;
1739     }
1740     if(bitidx==255)
1741       bitidx=0;
1742     warnings = 0;
1743     if(num_blocks == 4) break;
1744         }
1745         memcpy(outBlocks, Blocks, 16*num_blocks);
1746         return num_blocks;
1747 }
1748
1749 int IsBlock0PCF7931(uint8_t *Block) {
1750         // Assume RFU means 0 :)
1751         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
1752     return 1;
1753         if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
1754     return 1;
1755         return 0;
1756 }
1757
1758 int IsBlock1PCF7931(uint8_t *Block) {
1759         // Assume RFU means 0 :)
1760         if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
1761     if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
1762       return 1;
1763
1764         return 0;
1765 }
1766
1767 #define ALLOC 16
1768
1769 void ReadPCF7931() {
1770         uint8_t Blocks[8][17];
1771         uint8_t tmpBlocks[4][16];
1772         int i, j, ind, ind2, n;
1773         int num_blocks = 0;
1774         int max_blocks = 8;
1775         int ident = 0;
1776         int error = 0;
1777         int tries = 0;
1778
1779         memset(Blocks, 0, 8*17*sizeof(uint8_t));
1780
1781         do {
1782     memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
1783     n = DemodPCF7931((uint8_t**)tmpBlocks);
1784     if(!n)
1785       error++;
1786     if(error==10 && num_blocks == 0) {
1787       Dbprintf("Error, no tag or bad tag");
1788       return;
1789     }
1790     else if (tries==20 || error==10) {
1791       Dbprintf("Error reading the tag");
1792       Dbprintf("Here is the partial content");
1793       goto end;
1794     }
1795
1796     for(i=0; i<n; i++)
1797       Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
1798                tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
1799                tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
1800     if(!ident) {
1801       for(i=0; i<n; i++) {
1802         if(IsBlock0PCF7931(tmpBlocks[i])) {
1803           // Found block 0 ?
1804           if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
1805             // Found block 1!
1806             // \o/
1807             ident = 1;
1808             memcpy(Blocks[0], tmpBlocks[i], 16);
1809             Blocks[0][ALLOC] = 1;
1810             memcpy(Blocks[1], tmpBlocks[i+1], 16);
1811             Blocks[1][ALLOC] = 1;
1812             max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
1813             // Debug print
1814             Dbprintf("(dbg) Max blocks: %d", max_blocks);
1815             num_blocks = 2;
1816             // Handle following blocks
1817             for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
1818               if(j==n) j=0;
1819               if(j==i) break;
1820               memcpy(Blocks[ind2], tmpBlocks[j], 16);
1821               Blocks[ind2][ALLOC] = 1;
1822             }
1823             break;
1824           }
1825         }
1826       }
1827     }
1828     else {
1829       for(i=0; i<n; i++) { // Look for identical block in known blocks
1830         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
1831           for(j=0; j<max_blocks; j++) {
1832             if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
1833               // Found an identical block
1834               for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
1835                 if(ind2 < 0)
1836                   ind2 = max_blocks;
1837                 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
1838                   // Dbprintf("Tmp %d -> Block %d", ind, ind2);
1839                   memcpy(Blocks[ind2], tmpBlocks[ind], 16);
1840                   Blocks[ind2][ALLOC] = 1;
1841                   num_blocks++;
1842                   if(num_blocks == max_blocks) goto end;
1843                 }
1844               }
1845               for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
1846                 if(ind2 > max_blocks)
1847                   ind2 = 0;
1848                 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
1849                   // Dbprintf("Tmp %d -> Block %d", ind, ind2);
1850                   memcpy(Blocks[ind2], tmpBlocks[ind], 16);
1851                   Blocks[ind2][ALLOC] = 1;
1852                   num_blocks++;
1853                   if(num_blocks == max_blocks) goto end;
1854                 }
1855               }
1856             }
1857           }
1858         }
1859       }
1860     }
1861     tries++;
1862     if (BUTTON_PRESS()) return;
1863         } while (num_blocks != max_blocks);
1864 end:
1865         Dbprintf("-----------------------------------------");
1866         Dbprintf("Memory content:");
1867         Dbprintf("-----------------------------------------");
1868         for(i=0; i<max_blocks; i++) {
1869     if(Blocks[i][ALLOC]==1)
1870       Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
1871                Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
1872                Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
1873     else
1874       Dbprintf("<missing block %d>", i);
1875         }
1876         Dbprintf("-----------------------------------------");
1877
1878         return ;
1879 }
1880
1881
1882 //-----------------------------------
1883 // EM4469 / EM4305 routines
1884 //-----------------------------------
1885 #define FWD_CMD_LOGIN 0xC //including the even parity, binary mirrored
1886 #define FWD_CMD_WRITE 0xA
1887 #define FWD_CMD_READ 0x9
1888 #define FWD_CMD_DISABLE 0x5
1889
1890
1891 uint8_t forwardLink_data[64]; //array of forwarded bits
1892 uint8_t * forward_ptr; //ptr for forward message preparation
1893 uint8_t fwd_bit_sz; //forwardlink bit counter
1894 uint8_t * fwd_write_ptr; //forwardlink bit pointer
1895
1896 //====================================================================
1897 // prepares command bits
1898 // see EM4469 spec
1899 //====================================================================
1900 //--------------------------------------------------------------------
1901 uint8_t Prepare_Cmd( uint8_t cmd ) {
1902   //--------------------------------------------------------------------
1903
1904   *forward_ptr++ = 0; //start bit
1905   *forward_ptr++ = 0; //second pause for 4050 code
1906
1907   *forward_ptr++ = cmd;
1908   cmd >>= 1;
1909   *forward_ptr++ = cmd;
1910   cmd >>= 1;
1911   *forward_ptr++ = cmd;
1912   cmd >>= 1;
1913   *forward_ptr++ = cmd;
1914
1915   return 6; //return number of emited bits
1916 }
1917
1918 //====================================================================
1919 // prepares address bits
1920 // see EM4469 spec
1921 //====================================================================
1922
1923 //--------------------------------------------------------------------
1924 uint8_t Prepare_Addr( uint8_t addr ) {
1925   //--------------------------------------------------------------------
1926
1927   register uint8_t line_parity;
1928
1929   uint8_t i;
1930   line_parity = 0;
1931   for(i=0;i<6;i++) {
1932     *forward_ptr++ = addr;
1933     line_parity ^= addr;
1934     addr >>= 1;
1935   }
1936
1937   *forward_ptr++ = (line_parity & 1);
1938
1939   return 7; //return number of emited bits
1940 }
1941
1942 //====================================================================
1943 // prepares data bits intreleaved with parity bits
1944 // see EM4469 spec
1945 //====================================================================
1946
1947 //--------------------------------------------------------------------
1948 uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
1949   //--------------------------------------------------------------------
1950
1951   register uint8_t line_parity;
1952   register uint8_t column_parity;
1953   register uint8_t i, j;
1954   register uint16_t data;
1955
1956   data = data_low;
1957   column_parity = 0;
1958
1959   for(i=0; i<4; i++) {
1960     line_parity = 0;
1961     for(j=0; j<8; j++) {
1962       line_parity ^= data;
1963       column_parity ^= (data & 1) << j;
1964       *forward_ptr++ = data;
1965       data >>= 1;
1966     }
1967     *forward_ptr++ = line_parity;
1968     if(i == 1)
1969       data = data_hi;
1970   }
1971
1972   for(j=0; j<8; j++) {
1973     *forward_ptr++ = column_parity;
1974     column_parity >>= 1;
1975   }
1976   *forward_ptr = 0;
1977
1978   return 45; //return number of emited bits
1979 }
1980
1981 //====================================================================
1982 // Forward Link send function
1983 // Requires: forwarLink_data filled with valid bits (1 bit per byte)
1984 // fwd_bit_count set with number of bits to be sent
1985 //====================================================================
1986 void SendForward(uint8_t fwd_bit_count) {
1987
1988   fwd_write_ptr = forwardLink_data;
1989   fwd_bit_sz = fwd_bit_count;
1990
1991   LED_D_ON();
1992
1993   //Field on
1994   FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
1995   FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
1996   FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
1997
1998   // Give it a bit of time for the resonant antenna to settle.
1999   // And for the tag to fully power up
2000   SpinDelay(150);
2001
2002   // force 1st mod pulse (start gap must be longer for 4305)
2003   fwd_bit_sz--; //prepare next bit modulation
2004   fwd_write_ptr++;
2005   FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
2006   SpinDelayUs(55*8); //55 cycles off (8us each)for 4305
2007   FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
2008   FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
2009   SpinDelayUs(16*8); //16 cycles on (8us each)
2010
2011   // now start writting
2012   while(fwd_bit_sz-- > 0) { //prepare next bit modulation
2013     if(((*fwd_write_ptr++) & 1) == 1)
2014       SpinDelayUs(32*8); //32 cycles at 125Khz (8us each)
2015     else {
2016       //These timings work for 4469/4269/4305 (with the 55*8 above)
2017       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
2018       SpinDelayUs(23*8); //16-4 cycles off (8us each)
2019       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
2020       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
2021       SpinDelayUs(9*8); //16 cycles on (8us each)
2022     }
2023   }
2024 }
2025
2026 void EM4xLogin(uint32_t Password) {
2027
2028   uint8_t fwd_bit_count;
2029
2030   forward_ptr = forwardLink_data;
2031   fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
2032   fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
2033
2034   SendForward(fwd_bit_count);
2035
2036   //Wait for command to complete
2037   SpinDelay(20);
2038
2039 }
2040
2041 void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
2042
2043   uint8_t fwd_bit_count;
2044   uint8_t *dest = (uint8_t *)BigBuf;
2045   int m=0, i=0;
2046
2047   //If password mode do login
2048   if (PwdMode == 1) EM4xLogin(Pwd);
2049
2050   forward_ptr = forwardLink_data;
2051   fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
2052   fwd_bit_count += Prepare_Addr( Address );
2053
2054   m = sizeof(BigBuf);
2055   // Clear destination buffer before sending the command
2056   memset(dest, 128, m);
2057   // Connect the A/D to the peak-detected low-frequency path.
2058   SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
2059   // Now set up the SSC to get the ADC samples that are now streaming at us.
2060   FpgaSetupSsc();
2061
2062   SendForward(fwd_bit_count);
2063
2064   // Now do the acquisition
2065   i = 0;
2066   for(;;) {
2067     if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
2068       AT91C_BASE_SSC->SSC_THR = 0x43;
2069     }
2070     if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
2071       dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
2072       i++;
2073       if (i >= m) break;
2074     }
2075   }
2076   FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
2077   LED_D_OFF();
2078 }
2079
2080 void EM4xWriteWord(uint32_t Data, uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
2081
2082   uint8_t fwd_bit_count;
2083
2084   //If password mode do login
2085   if (PwdMode == 1) EM4xLogin(Pwd);
2086
2087   forward_ptr = forwardLink_data;
2088   fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
2089   fwd_bit_count += Prepare_Addr( Address );
2090   fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
2091
2092   SendForward(fwd_bit_count);
2093
2094   //Wait for write to complete
2095   SpinDelay(20);
2096   FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
2097   LED_D_OFF();
2098 }