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