]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/lfops.c
speed up the em4x05 cmds by only getting 6k...
[proxmark3-svn] / armsrc / lfops.c
index 6c9a36f7e51f42019173256eef92c3001f1251a5..cfe032fc45eab9277995a94843604886fa980094 100644 (file)
-//-----------------------------------------------------------------------------\r
-// Miscellaneous routines for low frequency tag operations.\r
-// Tags supported here so far are Texas Instruments (TI), HID\r
-// Also routines for raw mode reading/simulating of LF waveform\r
-//\r
-//-----------------------------------------------------------------------------\r
-#include <proxmark3.h>\r
-#include "apps.h"\r
-#include "hitag2.h"\r
-#include "../common/crc16.c"\r
-\r
-int sprintf(char *dest, const char *fmt, ...);\r
-\r
-void AcquireRawAdcSamples125k(BOOL at134khz)\r
-{\r
-       if(at134khz) {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       } else {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       }\r
-\r
-       // Connect the A/D to the peak-detected low-frequency path.\r
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);\r
-\r
-       // Give it a bit of time for the resonant antenna to settle.\r
-       SpinDelay(50);\r
-\r
-       // Now set up the SSC to get the ADC samples that are now streaming at us.\r
-       FpgaSetupSsc();\r
-\r
-       // Now call the acquisition routine\r
-       DoAcquisition125k(at134khz);\r
-}\r
-\r
-// split into two routines so we can avoid timing issues after sending commands //\r
-void DoAcquisition125k(BOOL at134khz)\r
-{\r
-       BYTE *dest = (BYTE *)BigBuf;\r
-       int n = sizeof(BigBuf);\r
-       int i;\r
-       char output_string[64];\r
-       \r
-       memset(dest,0,n);\r
-       i = 0;\r
-       for(;;) {\r
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {\r
-                       AT91C_BASE_SSC->SSC_THR = 0x43;\r
-                       LED_D_ON();\r
-               }\r
-               if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {\r
-                       dest[i] = (BYTE)AT91C_BASE_SSC->SSC_RHR;\r
-                       i++;\r
-                       LED_D_OFF();\r
-                       if (i >= n) break;\r
-               }\r
-       }\r
-       sprintf(output_string, "read samples, dest[0]=%x dest[1]=%x at134khz=%d",\r
-               dest[0], dest[1], at134khz);\r
-       DbpString(output_string);\r
-}\r
-\r
-void ModThenAcquireRawAdcSamples125k(int delay_off,int period_0,int period_1,BYTE *command)\r
-{\r
-       BOOL at134khz;\r
-\r
-       /* Make sure the tag is reset */\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
-       SpinDelay(2500);\r
-       \r
-       // see if 'h' was specified\r
-       if(command[strlen((char *) command) - 1] == 'h')\r
-               at134khz= TRUE;\r
-       else\r
-               at134khz= FALSE;\r
-\r
-       if(at134khz) {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       } else {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       }\r
-\r
-       // Give it a bit of time for the resonant antenna to settle.\r
-       SpinDelay(50);\r
-       // And a little more time for the tag to fully power up\r
-       SpinDelay(2000);\r
-\r
-       // Now set up the SSC to get the ADC samples that are now streaming at us.\r
-       FpgaSetupSsc();\r
-\r
-       // now modulate the reader field\r
-       while(*command != '\0' && *command != ' ')\r
-               {\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
-               LED_D_OFF();\r
-               SpinDelayUs(delay_off);\r
-               if(at134khz) {\r
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-               } else {\r
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
-                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-               }\r
-               LED_D_ON();\r
-               if(*(command++) == '0') {\r
-                       SpinDelayUs(period_0);\r
-               } else {\r
-                       SpinDelayUs(period_1);\r
-               }\r
-               }\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
-       LED_D_OFF();\r
-       SpinDelayUs(delay_off);\r
-       if(at134khz) {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       } else {\r
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-       }\r
-\r
-       // now do the read\r
-       DoAcquisition125k(at134khz);\r
-}\r
-\r
-/* blank r/w tag data stream\r
-...0000000000000000 01111111\r
-1010101010101010101010101010101010101010101010101010101010101010\r
-0011010010100001\r
-01111111\r
-101010101010101[0]000...\r
-\r
-[5555fe852c5555555555555555fe0000]\r
-*/\r
-void ReadTItag()\r
-{\r
-       // some hardcoded initial params\r
-       // when we read a TI tag we sample the zerocross line at 2Mhz\r
-       // TI tags modulate a 1 as 16 cycles of 123.2Khz\r
-       // TI tags modulate a 0 as 16 cycles of 134.2Khz\r
-       #define FSAMPLE 2000000\r
-       #define FREQLO 123200\r
-       #define FREQHI 134200\r
-\r
-       signed char *dest = (signed char *)BigBuf;\r
-       int n = sizeof(BigBuf);\r
-//     int *dest = GraphBuffer;\r
-//     int n = GraphTraceLen;\r
-\r
-       // 128 bit shift register [shift3:shift2:shift1:shift0]\r
-       DWORD shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;\r
-\r
-       int i, cycles=0, samples=0;\r
-       // how many sample points fit in 16 cycles of each frequency\r
-       DWORD sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;\r
-       // when to tell if we're close enough to one freq or another\r
-       DWORD threshold = (sampleslo - sampleshi + 1)>>1;\r
-\r
-       // TI tags charge at 134.2Khz\r
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-\r
-       // Place FPGA in passthrough mode, in this mode the CROSS_LO line\r
-       // connects to SSP_DIN and the SSP_DOUT logic level controls\r
-       // whether we're modulating the antenna (high)\r
-       // or listening to the antenna (low)\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);\r
-\r
-       // get TI tag data into the buffer\r
-       AcquireTiType();\r
-\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
-\r
-       for (i=0; i<n-1; i++) {\r
-               // count cycles by looking for lo to hi zero crossings\r
-               if ( (dest[i]<0) && (dest[i+1]>0) ) {\r
-                       cycles++;\r
-                       // after 16 cycles, measure the frequency\r
-                       if (cycles>15) {\r
-                               cycles=0;\r
-                               samples=i-samples; // number of samples in these 16 cycles\r
-\r
-                               // TI bits are coming to us lsb first so shift them\r
-                               // right through our 128 bit right shift register\r
-                         shift0 = (shift0>>1) | (shift1 << 31);\r
-                         shift1 = (shift1>>1) | (shift2 << 31);\r
-                         shift2 = (shift2>>1) | (shift3 << 31);\r
-                         shift3 >>= 1;\r
-\r
-                               // check if the cycles fall close to the number\r
-                               // expected for either the low or high frequency\r
-                               if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {\r
-                                       // low frequency represents a 1\r
-                                       shift3 |= (1<<31);\r
-                               } else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {\r
-                                       // high frequency represents a 0\r
-                               } else {\r
-                                       // probably detected a gay waveform or noise\r
-                                       // use this as gaydar or discard shift register and start again\r
-                                       shift3 = shift2 = shift1 = shift0 = 0;\r
-                               }\r
-                               samples = i;\r
-\r
-                               // for each bit we receive, test if we've detected a valid tag\r
-\r
-                               // if we see 17 zeroes followed by 6 ones, we might have a tag\r
-                               // remember the bits are backwards\r
-                               if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {\r
-                                       // if start and end bytes match, we have a tag so break out of the loop\r
-                                       if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {\r
-                                               cycles = 0xF0B; //use this as a flag (ugly but whatever)\r
-                                               break;\r
-                                       }\r
-                               }\r
-                       }\r
-               }\r
-       }\r
-\r
-       // if flag is set we have a tag\r
-       if (cycles!=0xF0B) {\r
-               DbpString("Info: No valid tag detected.");\r
-       } else {\r
-         // put 64 bit data into shift1 and shift0\r
-         shift0 = (shift0>>24) | (shift1 << 8);\r
-         shift1 = (shift1>>24) | (shift2 << 8);\r
-\r
-               // align 16 bit crc into lower half of shift2\r
-         shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;\r
-\r
-               // if r/w tag, check ident match\r
-               if ( shift3&(1<<15) ) {\r
-                       DbpString("Info: TI tag is rewriteable");\r
-                       // only 15 bits compare, last bit of ident is not valid\r
-                       if ( ((shift3>>16)^shift0)&0x7fff ) {\r
-                               DbpString("Error: Ident mismatch!");\r
-                       } else {\r
-                               DbpString("Info: TI tag ident is valid");\r
-                       }\r
-               } else {\r
-                       DbpString("Info: TI tag is readonly");\r
-               }\r
-\r
-               // WARNING the order of the bytes in which we calc crc below needs checking\r
-               // i'm 99% sure the crc algorithm is correct, but it may need to eat the\r
-               // bytes in reverse or something\r
-               // calculate CRC\r
-               DWORD crc=0;\r
-\r
-               crc = update_crc16(crc, (shift0)&0xff);\r
-               crc = update_crc16(crc, (shift0>>8)&0xff);\r
-               crc = update_crc16(crc, (shift0>>16)&0xff);\r
-               crc = update_crc16(crc, (shift0>>24)&0xff);\r
-               crc = update_crc16(crc, (shift1)&0xff);\r
-               crc = update_crc16(crc, (shift1>>8)&0xff);\r
-               crc = update_crc16(crc, (shift1>>16)&0xff);\r
-               crc = update_crc16(crc, (shift1>>24)&0xff);\r
-\r
-               char output_string[64];\r
-               sprintf(output_string, "Info: Tag data_hi=%x, data_lo=%x, crc=%x",\r
-                       (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);\r
-               DbpString(output_string);\r
-               if (crc != (shift2&0xffff)) {\r
-                       sprintf(output_string, "Error: CRC mismatch, expected %x", (unsigned int)crc);\r
-                       DbpString(output_string);\r
-               } else {\r
-                       DbpString("Info: CRC is good");\r
-               }\r
-       }\r
-}\r
-\r
-void WriteTIbyte(BYTE b)\r
-{\r
-       int i = 0;\r
-\r
-       // modulate 8 bits out to the antenna\r
-       for (i=0; i<8; i++)\r
-       {\r
-               if (b&(1<<i)) {\r
-                       // stop modulating antenna\r
-                       LOW(GPIO_SSC_DOUT);\r
-                       SpinDelayUs(1000);\r
-                       // modulate antenna\r
-                       HIGH(GPIO_SSC_DOUT);\r
-                       SpinDelayUs(1000);\r
-               } else {\r
-                       // stop modulating antenna\r
-                       LOW(GPIO_SSC_DOUT);\r
-                       SpinDelayUs(300);\r
-                       // modulate antenna\r
-                       HIGH(GPIO_SSC_DOUT);\r
-                       SpinDelayUs(1700);\r
-               }\r
-       }\r
-}\r
-\r
-void AcquireTiType(void)\r
-{\r
-       int i, j, n;\r
-       // tag transmission is <20ms, sampling at 2M gives us 40K samples max\r
-       // each sample is 1 bit stuffed into a DWORD so we need 1250 DWORDS\r
-       #define TIBUFLEN 1250\r
-\r
-       // clear buffer\r
-       memset(BigBuf,0,sizeof(BigBuf));\r
-\r
-       // Set up the synchronous serial port\r
-       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;\r
-       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN;\r
-\r
-       // steal this pin from the SSP and use it to control the modulation\r
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;\r
-       AT91C_BASE_PIOA->PIO_OER        = GPIO_SSC_DOUT;\r
-\r
-       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_SWRST;\r
-       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_RXEN | AT91C_SSC_TXEN;\r
-\r
-       // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long\r
-       // 48/2 = 24 MHz clock must be divided by 12\r
-       AT91C_BASE_SSC->SSC_CMR = 12;\r
-\r
-       AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(0);\r
-       AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(32) | AT91C_SSC_MSBF;\r
-       AT91C_BASE_SSC->SSC_TCMR = 0;\r
-       AT91C_BASE_SSC->SSC_TFMR = 0;\r
-\r
-       LED_D_ON();\r
-\r
-       // modulate antenna\r
-       HIGH(GPIO_SSC_DOUT);\r
-\r
-       // Charge TI tag for 50ms.\r
-       SpinDelay(50);\r
-\r
-       // stop modulating antenna and listen\r
-       LOW(GPIO_SSC_DOUT);\r
-\r
-       LED_D_OFF();\r
-\r
-       i = 0;\r
-       for(;;) {\r
-               if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {\r
-                       BigBuf[i] = AT91C_BASE_SSC->SSC_RHR;    // store 32 bit values in buffer\r
-                       i++; if(i >= TIBUFLEN) break;\r
-               }\r
-               WDT_HIT();\r
-       }\r
-\r
-       // return stolen pin to SSP\r
-       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;\r
-       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;\r
-\r
-       char *dest = (char *)BigBuf;\r
-       n = TIBUFLEN*32;\r
-       // unpack buffer\r
-       for (i=TIBUFLEN-1; i>=0; i--) {\r
-//             DbpIntegers(0, 0, BigBuf[i]);\r
-               for (j=0; j<32; j++) {\r
-                       if(BigBuf[i] & (1 << j)) {\r
-                               dest[--n] = 1;\r
-                       } else {\r
-                               dest[--n] = -1;\r
-                       }\r
-               }\r
-       }\r
-}\r
-\r
-// arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc\r
-// if crc provided, it will be written with the data verbatim (even if bogus)\r
-// if not provided a valid crc will be computed from the data and written.\r
-void WriteTItag(DWORD idhi, DWORD idlo, WORD crc)\r
-{\r
-\r
-       // WARNING the order of the bytes in which we calc crc below needs checking\r
-       // i'm 99% sure the crc algorithm is correct, but it may need to eat the\r
-       // bytes in reverse or something\r
-\r
-       if(crc == 0) {\r
-               crc = update_crc16(crc, (idlo)&0xff);\r
-               crc = update_crc16(crc, (idlo>>8)&0xff);\r
-               crc = update_crc16(crc, (idlo>>16)&0xff);\r
-               crc = update_crc16(crc, (idlo>>24)&0xff);\r
-               crc = update_crc16(crc, (idhi)&0xff);\r
-               crc = update_crc16(crc, (idhi>>8)&0xff);\r
-               crc = update_crc16(crc, (idhi>>16)&0xff);\r
-               crc = update_crc16(crc, (idhi>>24)&0xff);\r
-       }\r
-       char output_string[64];\r
-       sprintf(output_string, "Writing the following data to tag: %x, %x, %x",\r
-               (unsigned int) idhi, (unsigned int) idlo, crc);\r
-       DbpString(output_string);\r
-\r
-       // TI tags charge at 134.2Khz\r
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz\r
-       // Place FPGA in passthrough mode, in this mode the CROSS_LO line\r
-       // connects to SSP_DIN and the SSP_DOUT logic level controls\r
-       // whether we're modulating the antenna (high)\r
-       // or listening to the antenna (low)\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);\r
-       LED_A_ON();\r
-\r
-       // steal this pin from the SSP and use it to control the modulation\r
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;\r
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;\r
-\r
-       // writing algorithm:\r
-       // a high bit consists of a field off for 1ms and field on for 1ms\r
-       // a low bit consists of a field off for 0.3ms and field on for 1.7ms\r
-       // initiate a charge time of 50ms (field on) then immediately start writing bits\r
-       // start by writing 0xBB (keyword) and 0xEB (password)\r
-       // then write 80 bits of data (or 64 bit data + 16 bit crc if you prefer)\r
-       // finally end with 0x0300 (write frame)\r
-       // all data is sent lsb firts\r
-       // finish with 15ms programming time\r
-\r
-       // modulate antenna\r
-       HIGH(GPIO_SSC_DOUT);\r
-       SpinDelay(50);  // charge time\r
-\r
-       WriteTIbyte(0xbb); // keyword\r
-       WriteTIbyte(0xeb); // password\r
-       WriteTIbyte( (idlo    )&0xff );\r
-       WriteTIbyte( (idlo>>8 )&0xff );\r
-       WriteTIbyte( (idlo>>16)&0xff );\r
-       WriteTIbyte( (idlo>>24)&0xff );\r
-       WriteTIbyte( (idhi    )&0xff );\r
-       WriteTIbyte( (idhi>>8 )&0xff );\r
-       WriteTIbyte( (idhi>>16)&0xff );\r
-       WriteTIbyte( (idhi>>24)&0xff ); // data hi to lo\r
-       WriteTIbyte( (crc     )&0xff ); // crc lo\r
-       WriteTIbyte( (crc>>8  )&0xff ); // crc hi\r
-       WriteTIbyte(0x00); // write frame lo\r
-       WriteTIbyte(0x03); // write frame hi\r
-       HIGH(GPIO_SSC_DOUT);\r
-       SpinDelay(50);  // programming time\r
-\r
-       LED_A_OFF();\r
-\r
-       // get TI tag data into the buffer\r
-       AcquireTiType();\r
-\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);\r
-       DbpString("Now use tiread to check");\r
-}\r
-\r
-void SimulateTagLowFrequency(int period, int ledcontrol)\r
-{\r
-       int i;\r
-       BYTE *tab = (BYTE *)BigBuf;\r
-\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);\r
-\r
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;\r
-\r
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;\r
-       AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;\r
-\r
-#define SHORT_COIL()   LOW(GPIO_SSC_DOUT)\r
-#define OPEN_COIL()            HIGH(GPIO_SSC_DOUT)\r
-\r
-       i = 0;\r
-       for(;;) {\r
-               while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {\r
-                       if(BUTTON_PRESS()) {\r
-                               DbpString("Stopped");\r
-                               return;\r
-                       }\r
-                       WDT_HIT();\r
-               }\r
-\r
-               if (ledcontrol)\r
-                       LED_D_ON();\r
-\r
-               if(tab[i])\r
-                       OPEN_COIL();\r
-               else\r
-                       SHORT_COIL();\r
-\r
-               if (ledcontrol)\r
-                       LED_D_OFF();\r
-\r
-               while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {\r
-                       if(BUTTON_PRESS()) {\r
-                               DbpString("Stopped");\r
-                               return;\r
-                       }\r
-                       WDT_HIT();\r
-               }\r
-\r
-               i++;\r
-               if(i == period) i = 0;\r
-       }\r
-}\r
-\r
-/* Provides a framework for bidirectional LF tag communication\r
- * Encoding is currently Hitag2, but the general idea can probably\r
- * be transferred to other encodings.\r
- * \r
- * The new FPGA code will, for the LF simulator mode, give on SSC_FRAME\r
- * (PA15) a thresholded version of the signal from the ADC. Setting the\r
- * ADC path to the low frequency peak detection signal, will enable a\r
- * somewhat reasonable receiver for modulation on the carrier signal\r
- * that is generated by the reader. The signal is low when the reader\r
- * field is switched off, and high when the reader field is active. Due\r
- * to the way that the signal looks like, mostly only the rising edge is\r
- * useful, your mileage may vary.\r
- * \r
- * Neat perk: PA15 can not only be used as a bit-banging GPIO, but is also\r
- * TIOA1, which can be used as the capture input for timer 1. This should\r
- * make it possible to measure the exact edge-to-edge time, without processor\r
- * intervention.\r
- * \r
- * Arguments: divisor is the divisor to be sent to the FPGA (e.g. 95 for 125kHz)\r
- * t0 is the carrier frequency cycle duration in terms of MCK (384 for 125kHz)\r
- * \r
- * The following defines are in carrier periods: \r
- */\r
-#define HITAG_T_0_MIN 15 /* T[0] should be 18..22 */ \r
-#define HITAG_T_1_MIN 24 /* T[1] should be 26..30 */\r
-#define HITAG_T_EOF   40 /* T_EOF should be > 36 */\r
-#define HITAG_T_WRESP 208 /* T_wresp should be 204..212 */\r
-\r
-static void hitag_handle_frame(int t0, int frame_len, char *frame);\r
-//#define DEBUG_RA_VALUES 1\r
-#define DEBUG_FRAME_CONTENTS 1\r
-void SimulateTagLowFrequencyBidir(int divisor, int t0)\r
-{\r
-#if DEBUG_RA_VALUES || DEBUG_FRAME_CONTENTS\r
-       int i = 0;\r
-#endif\r
-       char frame[10];\r
-       int frame_pos=0;\r
-       \r
-       DbpString("Starting Hitag2 emulator, press button to end");\r
-       hitag2_init();\r
-       \r
-       /* Set up simulator mode, frequency divisor which will drive the FPGA\r
-        * and analog mux selection.\r
-        */\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);\r
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);\r
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);\r
-       RELAY_OFF();\r
-       \r
-       /* Set up Timer 1:\r
-        * Capture mode, timer source MCK/2 (TIMER_CLOCK1), TIOA is external trigger,\r
-        * external trigger rising edge, load RA on rising edge of TIOA, load RB on rising\r
-        * edge of TIOA. Assign PA15 to TIOA1 (peripheral B)\r
-        */\r
-       \r
-       AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);\r
-       AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME;\r
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;\r
-       AT91C_BASE_TC1->TC_CMR =        TC_CMR_TCCLKS_TIMER_CLOCK1 |\r
-                                                               AT91C_TC_ETRGEDG_RISING |\r
-                                                               AT91C_TC_ABETRG |\r
-                                                               AT91C_TC_LDRA_RISING |\r
-                                                               AT91C_TC_LDRB_RISING;\r
-       AT91C_BASE_TC1->TC_CCR =        AT91C_TC_CLKEN |\r
-                                                               AT91C_TC_SWTRG;\r
-       \r
-       /* calculate the new value for the carrier period in terms of TC1 values */\r
-       t0 = t0/2;\r
-       \r
-       int overflow = 0;\r
-       while(!BUTTON_PRESS()) {\r
-               WDT_HIT();\r
-               if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) {\r
-                       int ra = AT91C_BASE_TC1->TC_RA;\r
-                       if((ra > t0*HITAG_T_EOF) | overflow) ra = t0*HITAG_T_EOF+1;\r
-#if DEBUG_RA_VALUES\r
-                       if(ra > 255 || overflow) ra = 255;\r
-                       ((char*)BigBuf)[i] = ra;\r
-                       i = (i+1) % 8000;\r
-#endif\r
-                       \r
-                       if(overflow || (ra > t0*HITAG_T_EOF) || (ra < t0*HITAG_T_0_MIN)) {\r
-                               /* Ignore */\r
-                       } else if(ra >= t0*HITAG_T_1_MIN ) {\r
-                               /* '1' bit */\r
-                               if(frame_pos < 8*sizeof(frame)) {\r
-                                       frame[frame_pos / 8] |= 1<<( 7-(frame_pos%8) );\r
-                                       frame_pos++;\r
-                               }\r
-                       } else if(ra >= t0*HITAG_T_0_MIN) {\r
-                               /* '0' bit */\r
-                               if(frame_pos < 8*sizeof(frame)) {\r
-                                       frame[frame_pos / 8] |= 0<<( 7-(frame_pos%8) );\r
-                                       frame_pos++;\r
-                               }\r
-                       }\r
-                       \r
-                       overflow = 0;\r
-                       LED_D_ON();\r
-               } else {\r
-                       if(AT91C_BASE_TC1->TC_CV > t0*HITAG_T_EOF) {\r
-                               /* Minor nuisance: In Capture mode, the timer can not be\r
-                                * stopped by a Compare C. There's no way to stop the clock\r
-                                * in software, so we'll just have to note the fact that an\r
-                                * overflow happened and the next loaded timer value might\r
-                                * have wrapped. Also, this marks the end of frame, and the\r
-                                * still running counter can be used to determine the correct\r
-                                * time for the start of the reply.\r
-                                */ \r
-                               overflow = 1;\r
-                               \r
-                               if(frame_pos > 0) {\r
-                                       /* Have a frame, do something with it */\r
-#if DEBUG_FRAME_CONTENTS\r
-                                       ((char*)BigBuf)[i++] = frame_pos;\r
-                                       memcpy( ((char*)BigBuf)+i, frame, 7);\r
-                                       i+=7;\r
-                                       i = i % sizeof(BigBuf);\r
-#endif\r
-                                       hitag_handle_frame(t0, frame_pos, frame);\r
-                                       memset(frame, 0, sizeof(frame));\r
-                               }\r
-                               frame_pos = 0;\r
-\r
-                       }\r
-                       LED_D_OFF();\r
-               }\r
-       }\r
-       DbpString("All done");\r
-}\r
-\r
-static void hitag_send_bit(int t0, int bit) {\r
-       if(bit == 1) {\r
-               /* Manchester: Loaded, then unloaded */\r
-               LED_A_ON();\r
-               SHORT_COIL();\r
-               while(AT91C_BASE_TC1->TC_CV < t0*15);\r
-               OPEN_COIL();\r
-               while(AT91C_BASE_TC1->TC_CV < t0*31);\r
-               LED_A_OFF();\r
-       } else if(bit == 0) {\r
-               /* Manchester: Unloaded, then loaded */\r
-               LED_B_ON();\r
-               OPEN_COIL();\r
-               while(AT91C_BASE_TC1->TC_CV < t0*15);\r
-               SHORT_COIL();\r
-               while(AT91C_BASE_TC1->TC_CV < t0*31);\r
-               LED_B_OFF();\r
-       }\r
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset clock for the next bit */\r
-       \r
-}\r
-static void hitag_send_frame(int t0, int frame_len, const char const * frame, int fdt)\r
-{\r
-       OPEN_COIL();\r
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;\r
-       \r
-       /* Wait for HITAG_T_WRESP carrier periods after the last reader bit,\r
-        * not that since the clock counts since the rising edge, but T_wresp is\r
-        * with respect to the falling edge, we need to wait actually (T_wresp - T_g)\r
-        * periods. The gap time T_g varies (4..10).\r
-        */\r
-       while(AT91C_BASE_TC1->TC_CV < t0*(fdt-8));\r
-\r
-       int saved_cmr = AT91C_BASE_TC1->TC_CMR;\r
-       AT91C_BASE_TC1->TC_CMR &= ~AT91C_TC_ETRGEDG; /* Disable external trigger for the clock */\r
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset the clock and use it for response timing */\r
-       \r
-       int i;\r
-       for(i=0; i<5; i++)\r
-               hitag_send_bit(t0, 1); /* Start of frame */\r
-       \r
-       for(i=0; i<frame_len; i++) {\r
-               hitag_send_bit(t0, !!(frame[i/ 8] & (1<<( 7-(i%8) ))) );\r
-       }\r
-       \r
-       OPEN_COIL();\r
-       AT91C_BASE_TC1->TC_CMR = saved_cmr;\r
-}\r
-\r
-/* Callback structure to cleanly separate tag emulation code from the radio layer. */\r
-static int hitag_cb(const char* response_data, const int response_length, const int fdt, void *cb_cookie)\r
-{\r
-       hitag_send_frame(*(int*)cb_cookie, response_length, response_data, fdt);\r
-       return 0;\r
-}\r
-/* Frame length in bits, frame contents in MSBit first format */\r
-static void hitag_handle_frame(int t0, int frame_len, char *frame)\r
-{\r
-       hitag2_handle_command(frame, frame_len, hitag_cb, &t0);\r
-}\r
-\r
-// compose fc/8 fc/10 waveform\r
-static void fc(int c, int *n) {\r
-       BYTE *dest = (BYTE *)BigBuf;\r
-       int idx;\r
-\r
-       // for when we want an fc8 pattern every 4 logical bits\r
-       if(c==0) {\r
-               dest[((*n)++)]=1;\r
-               dest[((*n)++)]=1;\r
-               dest[((*n)++)]=0;\r
-               dest[((*n)++)]=0;\r
-               dest[((*n)++)]=0;\r
-               dest[((*n)++)]=0;\r
-               dest[((*n)++)]=0;\r
-               dest[((*n)++)]=0;\r
-       }\r
-       //      an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples\r
-       if(c==8) {\r
-               for (idx=0; idx<6; idx++) {\r
-                       dest[((*n)++)]=1;\r
-                       dest[((*n)++)]=1;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-               }\r
-       }\r
-\r
-       //      an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples\r
-       if(c==10) {\r
-               for (idx=0; idx<5; idx++) {\r
-                       dest[((*n)++)]=1;\r
-                       dest[((*n)++)]=1;\r
-                       dest[((*n)++)]=1;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-                       dest[((*n)++)]=0;\r
-               }\r
-       }\r
-}\r
-\r
-// prepare a waveform pattern in the buffer based on the ID given then\r
-// simulate a HID tag until the button is pressed\r
-void CmdHIDsimTAG(int hi, int lo, int ledcontrol)\r
-{\r
-       int n=0, i=0;\r
-       /*\r
-        HID tag bitstream format\r
-        The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits\r
-        A 1 bit is represented as 6 fc8 and 5 fc10 patterns\r
-        A 0 bit is represented as 5 fc10 and 6 fc8 patterns\r
-        A fc8 is inserted before every 4 bits\r
-        A special start of frame pattern is used consisting a0b0 where a and b are neither 0\r
-        nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)\r
-       */\r
-\r
-       if (hi>0xFFF) {\r
-               DbpString("Tags can only have 44 bits.");\r
-               return;\r
-       }\r
-       fc(0,&n);\r
-       // special start of frame marker containing invalid bit sequences\r
-       fc(8,  &n);     fc(8,  &n);     // invalid\r
-       fc(8,  &n);     fc(10, &n); // logical 0\r
-       fc(10, &n);     fc(10, &n); // invalid\r
-       fc(8,  &n);     fc(10, &n); // logical 0\r
-\r
-       WDT_HIT();\r
-       // manchester encode bits 43 to 32\r
-       for (i=11; i>=0; i--) {\r
-               if ((i%4)==3) fc(0,&n);\r
-               if ((hi>>i)&1) {\r
-                       fc(10, &n);     fc(8,  &n);             // low-high transition\r
-               } else {\r
-                       fc(8,  &n);     fc(10, &n);             // high-low transition\r
-               }\r
-       }\r
-\r
-       WDT_HIT();\r
-       // manchester encode bits 31 to 0\r
-       for (i=31; i>=0; i--) {\r
-               if ((i%4)==3) fc(0,&n);\r
-               if ((lo>>i)&1) {\r
-                       fc(10, &n);     fc(8,  &n);             // low-high transition\r
-               } else {\r
-                       fc(8,  &n);     fc(10, &n);             // high-low transition\r
-               }\r
-       }\r
-\r
-       if (ledcontrol)\r
-               LED_A_ON();\r
-       SimulateTagLowFrequency(n, ledcontrol);\r
-\r
-       if (ledcontrol)\r
-               LED_A_OFF();\r
-}\r
-\r
-\r
-// loop to capture raw HID waveform then FSK demodulate the TAG ID from it\r
-void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)\r
-{\r
-       BYTE *dest = (BYTE *)BigBuf;\r
-       int m=0, n=0, i=0, idx=0, found=0, lastval=0;\r
-       DWORD hi=0, lo=0;\r
-\r
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz\r
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);\r
-\r
-       // Connect the A/D to the peak-detected low-frequency path.\r
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);\r
-\r
-       // Give it a bit of time for the resonant antenna to settle.\r
-       SpinDelay(50);\r
-\r
-       // Now set up the SSC to get the ADC samples that are now streaming at us.\r
-       FpgaSetupSsc();\r
-\r
-       for(;;) {\r
-               WDT_HIT();\r
-               if (ledcontrol)\r
-                       LED_A_ON();\r
-               if(BUTTON_PRESS()) {\r
-                       DbpString("Stopped");\r
-                       if (ledcontrol)\r
-                               LED_A_OFF();\r
-                       return;\r
-               }\r
-\r
-               i = 0;\r
-               m = sizeof(BigBuf);\r
-               memset(dest,128,m);\r
-               for(;;) {\r
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {\r
-                               AT91C_BASE_SSC->SSC_THR = 0x43;\r
-                               if (ledcontrol)\r
-                                       LED_D_ON();\r
-                       }\r
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {\r
-                               dest[i] = (BYTE)AT91C_BASE_SSC->SSC_RHR;\r
-                               // we don't care about actual value, only if it's more or less than a\r
-                               // threshold essentially we capture zero crossings for later analysis\r
-                               if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;\r
-                               i++;\r
-                               if (ledcontrol)\r
-                                       LED_D_OFF();\r
-                               if(i >= m) {\r
-                                       break;\r
-                               }\r
-                       }\r
-               }\r
-\r
-               // FSK demodulator\r
-\r
-               // sync to first lo-hi transition\r
-               for( idx=1; idx<m; idx++) {\r
-                       if (dest[idx-1]<dest[idx])\r
-                               lastval=idx;\r
-                               break;\r
-               }\r
-               WDT_HIT();\r
-\r
-               // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)\r
-               // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere\r
-               // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10\r
-               for( i=0; idx<m; idx++) {\r
-                       if (dest[idx-1]<dest[idx]) {\r
-                               dest[i]=idx-lastval;\r
-                               if (dest[i] <= 8) {\r
-                                               dest[i]=1;\r
-                               } else {\r
-                                               dest[i]=0;\r
-                               }\r
-\r
-                               lastval=idx;\r
-                               i++;\r
-                       }\r
-               }\r
-               m=i;\r
-               WDT_HIT();\r
-\r
-               // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns\r
-               lastval=dest[0];\r
-               idx=0;\r
-               i=0;\r
-               n=0;\r
-               for( idx=0; idx<m; idx++) {\r
-                       if (dest[idx]==lastval) {\r
-                               n++;\r
-                       } else {\r
-                               // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,\r
-                               // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets\r
-                               // swallowed up by rounding\r
-                               // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding\r
-                               // special start of frame markers use invalid manchester states (no transitions) by using sequences\r
-                               // like 111000\r
-                               if (dest[idx-1]) {\r
-                                       n=(n+1)/6;                      // fc/8 in sets of 6\r
-                               } else {\r
-                                       n=(n+1)/5;                      // fc/10 in sets of 5\r
-                               }\r
-                               switch (n) {                    // stuff appropriate bits in buffer\r
-                                       case 0:\r
-                                       case 1: // one bit\r
-                                               dest[i++]=dest[idx-1];\r
-                                               break;\r
-                                       case 2: // two bits\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               break;\r
-                                       case 3: // 3 bit start of frame markers\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               break;\r
-                                       // When a logic 0 is immediately followed by the start of the next transmisson\r
-                                       // (special pattern) a pattern of 4 bit duration lengths is created.\r
-                                       case 4:\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               dest[i++]=dest[idx-1];\r
-                                               break;\r
-                                       default:        // this shouldn't happen, don't stuff any bits\r
-                                               break;\r
-                               }\r
-                               n=0;\r
-                               lastval=dest[idx];\r
-                       }\r
-               }\r
-               m=i;\r
-               WDT_HIT();\r
-\r
-               // final loop, go over previously decoded manchester data and decode into usable tag ID\r
-               // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0\r
-               for( idx=0; idx<m-6; idx++) {\r
-                       // search for a start of frame marker\r
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )\r
-                       {\r
-                               found=1;\r
-                               idx+=6;\r
-                               if (found && (hi|lo)) {\r
-                                       char output_string[64];\r
-                                       sprintf(output_string, "TAG ID: %x %x %x", \r
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);\r
-                                       DbpString(output_string);\r
-                                       /* if we're only looking for one tag */\r
-                                       if (findone)\r
-                                       {\r
-                                               *high = hi;\r
-                                               *low = lo;\r
-                                               return;\r
-                                       }\r
-                                       hi=0;\r
-                                       lo=0;\r
-                                       found=0;\r
-                               }\r
-                       }\r
-                       if (found) {\r
-                               if (dest[idx] && (!dest[idx+1]) ) {\r
-                                       hi=(hi<<1)|(lo>>31);\r
-                                       lo=(lo<<1)|0;\r
-                               } else if ( (!dest[idx]) && dest[idx+1]) {\r
-                                       hi=(hi<<1)|(lo>>31);\r
-                                       lo=(lo<<1)|1;\r
-                               } else {\r
-                                       found=0;\r
-                                       hi=0;\r
-                                       lo=0;\r
-                               }\r
-                               idx++;\r
-                       }\r
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )\r
-                       {\r
-                               found=1;\r
-                               idx+=6;\r
-                               if (found && (hi|lo)) {\r
-                                       char output_string[64];\r
-                                       sprintf(output_string, "TAG ID: %x %x %x", \r
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);\r
-                                       DbpString(output_string);\r
-                                       /* if we're only looking for one tag */\r
-                                       if (findone)\r
-                                       {\r
-                                               *high = hi;\r
-                                               *low = lo;\r
-                                               return;\r
-                                       }\r
-                                       hi=0;\r
-                                       lo=0;\r
-                                       found=0;\r
-                               }\r
-                       }\r
-               }\r
-               WDT_HIT();\r
-       }\r
-}\r
+//-----------------------------------------------------------------------------
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Miscellaneous routines for low frequency tag operations.
+// Tags supported here so far are Texas Instruments (TI), HID
+// Also routines for raw mode reading/simulating of LF waveform
+//-----------------------------------------------------------------------------
+
+#include "proxmark3.h"
+#include "apps.h"
+#include "util.h"
+#include "hitag2.h"
+#include "crc16.h"
+#include "string.h"
+#include "lfdemod.h"
+#include "lfsampling.h"
+#include "protocols.h"
+#include "usb_cdc.h" // for usb_poll_validate_length
+
+/**
+ * Function to do a modulation and then get samples.
+ * @param delay_off
+ * @param period_0
+ * @param period_1
+ * @param command
+ */
+void ModThenAcquireRawAdcSamples125k(uint32_t delay_off, uint32_t period_0, uint32_t period_1, uint8_t *command)
+{
+
+       int divisor_used = 95; // 125 KHz
+       // see if 'h' was specified
+
+       if (command[strlen((char *) command) - 1] == 'h')
+               divisor_used = 88; // 134.8 KHz
+
+       sample_config sc = { 0,0,1, divisor_used, 0};
+       setSamplingConfig(&sc);
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+
+       /* Make sure the tag is reset */
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelay(2500);
+
+       LFSetupFPGAForADC(sc.divisor, 1);
+
+       // And a little more time for the tag to fully power up
+       SpinDelay(2000);
+
+       // now modulate the reader field
+       while(*command != '\0' && *command != ' ') {
+               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+               LED_D_OFF();
+               SpinDelayUs(delay_off);
+               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, sc.divisor);
+
+               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+               LED_D_ON();
+               if(*(command++) == '0')
+                       SpinDelayUs(period_0);
+               else
+                       SpinDelayUs(period_1);
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       LED_D_OFF();
+       SpinDelayUs(delay_off);
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, sc.divisor);
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+       // now do the read
+       DoAcquisition_config(false);
+}
+
+/* blank r/w tag data stream
+...0000000000000000 01111111
+1010101010101010101010101010101010101010101010101010101010101010
+0011010010100001
+01111111
+101010101010101[0]000...
+
+[5555fe852c5555555555555555fe0000]
+*/
+void ReadTItag(void)
+{
+       // some hardcoded initial params
+       // when we read a TI tag we sample the zerocross line at 2Mhz
+       // TI tags modulate a 1 as 16 cycles of 123.2Khz
+       // TI tags modulate a 0 as 16 cycles of 134.2Khz
+ #define FSAMPLE 2000000
+ #define FREQLO 123200
+ #define FREQHI 134200
+
+       signed char *dest = (signed char *)BigBuf_get_addr();
+       uint16_t n = BigBuf_max_traceLen();
+       // 128 bit shift register [shift3:shift2:shift1:shift0]
+       uint32_t shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
+
+       int i, cycles=0, samples=0;
+       // how many sample points fit in 16 cycles of each frequency
+       uint32_t sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
+       // when to tell if we're close enough to one freq or another
+       uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
+
+       // TI tags charge at 134.2Khz
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+
+       // Place FPGA in passthrough mode, in this mode the CROSS_LO line
+       // connects to SSP_DIN and the SSP_DOUT logic level controls
+       // whether we're modulating the antenna (high)
+       // or listening to the antenna (low)
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
+
+       // get TI tag data into the buffer
+       AcquireTiType();
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+
+       for (i=0; i<n-1; i++) {
+               // count cycles by looking for lo to hi zero crossings
+               if ( (dest[i]<0) && (dest[i+1]>0) ) {
+                       cycles++;
+                       // after 16 cycles, measure the frequency
+                       if (cycles>15) {
+                               cycles=0;
+                               samples=i-samples; // number of samples in these 16 cycles
+
+                               // TI bits are coming to us lsb first so shift them
+                               // right through our 128 bit right shift register
+                               shift0 = (shift0>>1) | (shift1 << 31);
+                               shift1 = (shift1>>1) | (shift2 << 31);
+                               shift2 = (shift2>>1) | (shift3 << 31);
+                               shift3 >>= 1;
+
+                               // check if the cycles fall close to the number
+                               // expected for either the low or high frequency
+                               if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {
+                                       // low frequency represents a 1
+                                       shift3 |= (1<<31);
+                               } else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {
+                                       // high frequency represents a 0
+                               } else {
+                                       // probably detected a gay waveform or noise
+                                       // use this as gaydar or discard shift register and start again
+                                       shift3 = shift2 = shift1 = shift0 = 0;
+                               }
+                               samples = i;
+
+                               // for each bit we receive, test if we've detected a valid tag
+
+                               // if we see 17 zeroes followed by 6 ones, we might have a tag
+                               // remember the bits are backwards
+                               if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {
+                                       // if start and end bytes match, we have a tag so break out of the loop
+                                       if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {
+                                               cycles = 0xF0B; //use this as a flag (ugly but whatever)
+                                               break;
+                                       }
+                               }
+                       }
+               }
+       }
+
+       // if flag is set we have a tag
+       if (cycles!=0xF0B) {
+               DbpString("Info: No valid tag detected.");
+       } else {
+               // put 64 bit data into shift1 and shift0
+               shift0 = (shift0>>24) | (shift1 << 8);
+               shift1 = (shift1>>24) | (shift2 << 8);
+
+               // align 16 bit crc into lower half of shift2
+               shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+
+               // if r/w tag, check ident match
+               if (shift3 & (1<<15) ) {
+                       DbpString("Info: TI tag is rewriteable");
+                       // only 15 bits compare, last bit of ident is not valid
+                       if (((shift3 >> 16) ^ shift0) & 0x7fff ) {
+                               DbpString("Error: Ident mismatch!");
+                       } else {
+                               DbpString("Info: TI tag ident is valid");
+                       }
+               } else {
+                       DbpString("Info: TI tag is readonly");
+               }
+
+               // WARNING the order of the bytes in which we calc crc below needs checking
+               // i'm 99% sure the crc algorithm is correct, but it may need to eat the
+               // bytes in reverse or something
+               // calculate CRC
+               uint32_t crc=0;
+
+               crc = update_crc16(crc, (shift0)&0xff);
+               crc = update_crc16(crc, (shift0>>8)&0xff);
+               crc = update_crc16(crc, (shift0>>16)&0xff);
+               crc = update_crc16(crc, (shift0>>24)&0xff);
+               crc = update_crc16(crc, (shift1)&0xff);
+               crc = update_crc16(crc, (shift1>>8)&0xff);
+               crc = update_crc16(crc, (shift1>>16)&0xff);
+               crc = update_crc16(crc, (shift1>>24)&0xff);
+
+               Dbprintf("Info: Tag data: %x%08x, crc=%x",
+                                (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
+               if (crc != (shift2&0xffff)) {
+                       Dbprintf("Error: CRC mismatch, expected %x", (unsigned int)crc);
+               } else {
+                       DbpString("Info: CRC is good");
+               }
+       }
+}
+
+void WriteTIbyte(uint8_t b)
+{
+       int i = 0;
+
+       // modulate 8 bits out to the antenna
+       for (i=0; i<8; i++)
+       {
+               if (b&(1<<i)) {
+                       // stop modulating antenna
+                       LOW(GPIO_SSC_DOUT);
+                       SpinDelayUs(1000);
+                       // modulate antenna
+                       HIGH(GPIO_SSC_DOUT);
+                       SpinDelayUs(1000);
+               } else {
+                       // stop modulating antenna
+                       LOW(GPIO_SSC_DOUT);
+                       SpinDelayUs(300);
+                       // modulate antenna
+                       HIGH(GPIO_SSC_DOUT);
+                       SpinDelayUs(1700);
+               }
+       }
+}
+
+void AcquireTiType(void)
+{
+       int i, j, n;
+       // tag transmission is <20ms, sampling at 2M gives us 40K samples max
+       // each sample is 1 bit stuffed into a uint32_t so we need 1250 uint32_t
+ #define TIBUFLEN 1250
+
+       // clear buffer
+       uint32_t *BigBuf = (uint32_t *)BigBuf_get_addr();
+       BigBuf_Clear_ext(false);
+
+       // Set up the synchronous serial port
+       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;
+       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN;
+
+       // steal this pin from the SSP and use it to control the modulation
+       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_SWRST;
+       AT91C_BASE_SSC->SSC_CR = AT91C_SSC_RXEN | AT91C_SSC_TXEN;
+
+       // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long
+       // 48/2 = 24 MHz clock must be divided by 12
+       AT91C_BASE_SSC->SSC_CMR = 12;
+
+       AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(0);
+       AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(32) | AT91C_SSC_MSBF;
+       AT91C_BASE_SSC->SSC_TCMR = 0;
+       AT91C_BASE_SSC->SSC_TFMR = 0;
+
+       LED_D_ON();
+
+       // modulate antenna
+       HIGH(GPIO_SSC_DOUT);
+
+       // Charge TI tag for 50ms.
+       SpinDelay(50);
+
+       // stop modulating antenna and listen
+       LOW(GPIO_SSC_DOUT);
+
+       LED_D_OFF();
+
+       i = 0;
+       for(;;) {
+               if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+                       BigBuf[i] = AT91C_BASE_SSC->SSC_RHR;    // store 32 bit values in buffer
+                       i++; if(i >= TIBUFLEN) break;
+               }
+               WDT_HIT();
+       }
+
+       // return stolen pin to SSP
+       AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
+       AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
+
+       char *dest = (char *)BigBuf_get_addr();
+       n = TIBUFLEN*32;
+       // unpack buffer
+       for (i=TIBUFLEN-1; i>=0; i--) {
+               for (j=0; j<32; j++) {
+                       if(BigBuf[i] & (1 << j)) {
+                               dest[--n] = 1;
+                       } else {
+                               dest[--n] = -1;
+                       }
+               }
+       }
+}
+
+// arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc
+// if crc provided, it will be written with the data verbatim (even if bogus)
+// if not provided a valid crc will be computed from the data and written.
+void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
+{
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+       if(crc == 0) {
+               crc = update_crc16(crc, (idlo)&0xff);
+               crc = update_crc16(crc, (idlo>>8)&0xff);
+               crc = update_crc16(crc, (idlo>>16)&0xff);
+               crc = update_crc16(crc, (idlo>>24)&0xff);
+               crc = update_crc16(crc, (idhi)&0xff);
+               crc = update_crc16(crc, (idhi>>8)&0xff);
+               crc = update_crc16(crc, (idhi>>16)&0xff);
+               crc = update_crc16(crc, (idhi>>24)&0xff);
+       }
+       Dbprintf("Writing to tag: %x%08x, crc=%x",
+                       (unsigned int) idhi, (unsigned int) idlo, crc);
+
+       // TI tags charge at 134.2Khz
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+       // Place FPGA in passthrough mode, in this mode the CROSS_LO line
+       // connects to SSP_DIN and the SSP_DOUT logic level controls
+       // whether we're modulating the antenna (high)
+       // or listening to the antenna (low)
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
+       LED_A_ON();
+
+       // steal this pin from the SSP and use it to control the modulation
+       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+       // writing algorithm:
+       // a high bit consists of a field off for 1ms and field on for 1ms
+       // a low bit consists of a field off for 0.3ms and field on for 1.7ms
+       // initiate a charge time of 50ms (field on) then immediately start writing bits
+       // start by writing 0xBB (keyword) and 0xEB (password)
+       // then write 80 bits of data (or 64 bit data + 16 bit crc if you prefer)
+       // finally end with 0x0300 (write frame)
+       // all data is sent lsb firts
+       // finish with 15ms programming time
+
+       // modulate antenna
+       HIGH(GPIO_SSC_DOUT);
+       SpinDelay(50);  // charge time
+
+       WriteTIbyte(0xbb); // keyword
+       WriteTIbyte(0xeb); // password
+       WriteTIbyte( (idlo    )&0xff );
+       WriteTIbyte( (idlo>>8 )&0xff );
+       WriteTIbyte( (idlo>>16)&0xff );
+       WriteTIbyte( (idlo>>24)&0xff );
+       WriteTIbyte( (idhi    )&0xff );
+       WriteTIbyte( (idhi>>8 )&0xff );
+       WriteTIbyte( (idhi>>16)&0xff );
+       WriteTIbyte( (idhi>>24)&0xff ); // data hi to lo
+       WriteTIbyte( (crc     )&0xff ); // crc lo
+       WriteTIbyte( (crc>>8  )&0xff ); // crc hi
+       WriteTIbyte(0x00); // write frame lo
+       WriteTIbyte(0x03); // write frame hi
+       HIGH(GPIO_SSC_DOUT);
+       SpinDelay(50);  // programming time
+
+       LED_A_OFF();
+
+       // get TI tag data into the buffer
+       AcquireTiType();
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Now use `lf ti read` to check");
+}
+
+void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
+{
+       int i;
+       uint8_t *tab = BigBuf_get_addr();
+
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
+
+       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
+
+       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+       AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
+
+ #define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
+ #define OPEN_COIL()    HIGH(GPIO_SSC_DOUT)
+
+       i = 0;
+       for(;;) {
+               //wait until SSC_CLK goes HIGH
+               while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
+                       if(BUTTON_PRESS() || (usb_poll_validate_length() )) {
+                               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                               DbpString("Stopped");
+                               return;
+                       }
+                       WDT_HIT();
+               }
+               if (ledcontrol)
+                       LED_D_ON();
+
+               if(tab[i])
+                       OPEN_COIL();
+               else
+                       SHORT_COIL();
+
+               if (ledcontrol)
+                       LED_D_OFF();
+               //wait until SSC_CLK goes LOW
+               while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
+                       if(BUTTON_PRESS() || (usb_poll_validate_length() )) {
+                               DbpString("Stopped");
+                               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                               return;
+                       }
+                       WDT_HIT();
+               }
+
+               i++;
+               if(i == period) {
+
+                       i = 0;
+                       if (gap) {
+                               SHORT_COIL();
+                               SpinDelayUs(gap);
+                       }
+               }
+
+       }
+}
+
+#define DEBUG_FRAME_CONTENTS 1
+void SimulateTagLowFrequencyBidir(int divisor, int t0)
+{
+}
+
+// compose fc/8 fc/10 waveform (FSK2)
+static void fc(int c, int *n)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       int idx;
+
+       // for when we want an fc8 pattern every 4 logical bits
+       if(c==0) {
+               dest[((*n)++)]=1;
+               dest[((*n)++)]=1;
+               dest[((*n)++)]=1;
+               dest[((*n)++)]=1;
+               dest[((*n)++)]=0;
+               dest[((*n)++)]=0;
+               dest[((*n)++)]=0;
+               dest[((*n)++)]=0;
+       }
+
+       //      an fc/8  encoded bit is a bit pattern of  11110000  x6 = 48 samples
+       if(c==8) {
+               for (idx=0; idx<6; idx++) {
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+               }
+       }
+
+       //      an fc/10 encoded bit is a bit pattern of 1111100000 x5 = 50 samples
+       if(c==10) {
+               for (idx=0; idx<5; idx++) {
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=0;
+               }
+       }
+}
+// compose fc/X fc/Y waveform (FSKx)
+static void fcAll(uint8_t fc, int *n, uint8_t clock, uint16_t *modCnt) 
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfFC = fc/2;
+       uint8_t wavesPerClock = clock/fc;
+       uint8_t mod = clock % fc;    //modifier
+       uint8_t modAdj = fc/mod;     //how often to apply modifier
+       bool modAdjOk = !(fc % mod); //if (fc % mod==0) modAdjOk=TRUE;
+       // loop through clock - step field clock
+       for (uint8_t idx=0; idx < wavesPerClock; idx++){
+               // put 1/2 FC length 1's and 1/2 0's per field clock wave (to create the wave)
+               memset(dest+(*n), 0, fc-halfFC);  //in case of odd number use extra here
+               memset(dest+(*n)+(fc-halfFC), 1, halfFC);
+               *n += fc;
+       }
+       if (mod>0) (*modCnt)++;
+       if ((mod>0) && modAdjOk){  //fsk2 
+               if ((*modCnt % modAdj) == 0){ //if 4th 8 length wave in a rf/50 add extra 8 length wave
+                       memset(dest+(*n), 0, fc-halfFC);
+                       memset(dest+(*n)+(fc-halfFC), 1, halfFC);
+                       *n += fc;
+               }
+       }
+       if (mod>0 && !modAdjOk){  //fsk1
+               memset(dest+(*n), 0, mod-(mod/2));
+               memset(dest+(*n)+(mod-(mod/2)), 1, mod/2);
+               *n += mod;
+       }
+}
+
+// prepare a waveform pattern in the buffer based on the ID given then
+// simulate a HID tag until the button is pressed
+void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
+{
+       int n=0, i=0;
+       /*
+        HID tag bitstream format
+        The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
+        A 1 bit is represented as 6 fc8 and 5 fc10 patterns
+        A 0 bit is represented as 5 fc10 and 6 fc8 patterns
+        A fc8 is inserted before every 4 bits
+        A special start of frame pattern is used consisting a0b0 where a and b are neither 0
+        nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
+       */
+
+       if (hi>0xFFF) {
+               DbpString("Tags can only have 44 bits. - USE lf simfsk for larger tags");
+               return;
+       }
+       fc(0,&n);
+       // special start of frame marker containing invalid bit sequences
+       fc(8,  &n);     fc(8,  &n); // invalid
+       fc(8,  &n);     fc(10, &n); // logical 0
+       fc(10, &n);     fc(10, &n); // invalid
+       fc(8,  &n);     fc(10, &n); // logical 0
+
+       WDT_HIT();
+       // manchester encode bits 43 to 32
+       for (i=11; i>=0; i--) {
+               if ((i%4)==3) fc(0,&n);
+               if ((hi>>i)&1) {
+                       fc(10, &n); fc(8,  &n);         // low-high transition
+               } else {
+                       fc(8,  &n); fc(10, &n);         // high-low transition
+               }
+       }
+
+       WDT_HIT();
+       // manchester encode bits 31 to 0
+       for (i=31; i>=0; i--) {
+               if ((i%4)==3) fc(0,&n);
+               if ((lo>>i)&1) {
+                       fc(10, &n); fc(8,  &n);         // low-high transition
+               } else {
+                       fc(8,  &n); fc(10, &n);         // high-low transition
+               }
+       }
+
+       if (ledcontrol)
+               LED_A_ON();
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+
+       if (ledcontrol)
+               LED_A_OFF();
+}
+
+// prepare a waveform pattern in the buffer based on the ID given then
+// simulate a FSK tag until the button is pressed
+// arg1 contains fcHigh and fcLow, arg2 contains invert and clock
+void CmdFSKsimTAG(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
+{
+       int ledcontrol=1;
+       int n=0, i=0;
+       uint8_t fcHigh = arg1 >> 8;
+       uint8_t fcLow = arg1 & 0xFF;
+       uint16_t modCnt = 0;
+       uint8_t clk = arg2 & 0xFF;
+       uint8_t invert = (arg2 >> 8) & 1;
+
+       for (i=0; i<size; i++){
+               if (BitStream[i] == invert){
+                       fcAll(fcLow, &n, clk, &modCnt);
+               } else {
+                       fcAll(fcHigh, &n, clk, &modCnt);
+               }
+       }
+       Dbprintf("Simulating with fcHigh: %d, fcLow: %d, clk: %d, invert: %d, n: %d",fcHigh, fcLow, clk, invert, n);
+       /*Dbprintf("DEBUG: First 32:");
+       uint8_t *dest = BigBuf_get_addr();
+       i=0;
+       Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       i+=16;
+       Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       */
+       if (ledcontrol)
+               LED_A_ON();
+
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+
+       if (ledcontrol)
+               LED_A_OFF();
+}
+
+// compose ask waveform for one bit(ASK)
+static void askSimBit(uint8_t c, int *n, uint8_t clock, uint8_t manchester)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       // c = current bit 1 or 0
+       if (manchester==1){
+               memset(dest+(*n), c, halfClk);
+               memset(dest+(*n) + halfClk, c^1, halfClk);
+       } else {
+               memset(dest+(*n), c, clock);
+       }
+       *n += clock;
+}
+
+static void biphaseSimBit(uint8_t c, int *n, uint8_t clock, uint8_t *phase)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       if (c){
+               memset(dest+(*n), c ^ 1 ^ *phase, halfClk);
+               memset(dest+(*n) + halfClk, c ^ *phase, halfClk);
+       } else {
+               memset(dest+(*n), c ^ *phase, clock);
+               *phase ^= 1;
+       }
+       *n += clock;
+}
+
+static void stAskSimBit(int *n, uint8_t clock) {
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       //ST = .5 high .5 low 1.5 high .5 low 1 high    
+       memset(dest+(*n), 1, halfClk);
+       memset(dest+(*n) + halfClk, 0, halfClk);
+       memset(dest+(*n) + clock, 1, clock + halfClk);
+       memset(dest+(*n) + clock*2 + halfClk, 0, halfClk);
+       memset(dest+(*n) + clock*3, 1, clock);
+       *n += clock*4;
+}
+
+// args clock, ask/man or askraw, invert, transmission separator
+void CmdASKsimTag(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
+{
+       int ledcontrol = 1;
+       int n=0, i=0;
+       uint8_t clk = (arg1 >> 8) & 0xFF;
+       uint8_t encoding = arg1 & 0xFF;
+       uint8_t separator = arg2 & 1;
+       uint8_t invert = (arg2 >> 8) & 1;
+
+       if (encoding==2){  //biphase
+               uint8_t phase=0;
+               for (i=0; i<size; i++){
+                       biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
+               }
+               if (phase==1) { //run a second set inverted to keep phase in check
+                       for (i=0; i<size; i++){
+                               biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
+                       }
+               }
+       } else {  // ask/manchester || ask/raw
+               for (i=0; i<size; i++){
+                       askSimBit(BitStream[i]^invert, &n, clk, encoding);
+               }
+               if (encoding==0 && BitStream[0]==BitStream[size-1]){ //run a second set inverted (for ask/raw || biphase phase)
+                       for (i=0; i<size; i++){
+                               askSimBit(BitStream[i]^invert^1, &n, clk, encoding);
+                       }
+               }
+       }
+       if (separator==1 && encoding == 1)
+               stAskSimBit(&n, clk);
+       else if (separator==1)
+               Dbprintf("sorry but separator option not yet available");
+
+       Dbprintf("Simulating with clk: %d, invert: %d, encoding: %d, separator: %d, n: %d",clk, invert, encoding, separator, n);
+       //DEBUG
+       //Dbprintf("First 32:");
+       //uint8_t *dest = BigBuf_get_addr();
+       //i=0;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       //i+=16;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       
+       if (ledcontrol) LED_A_ON();
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+       if (ledcontrol) LED_A_OFF();
+}
+
+//carrier can be 2,4 or 8
+static void pskSimBit(uint8_t waveLen, int *n, uint8_t clk, uint8_t *curPhase, bool phaseChg)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfWave = waveLen/2;
+       //uint8_t idx;
+       int i = 0;
+       if (phaseChg){
+               // write phase change
+               memset(dest+(*n), *curPhase^1, halfWave);
+               memset(dest+(*n) + halfWave, *curPhase, halfWave);
+               *n += waveLen;
+               *curPhase ^= 1;
+               i += waveLen;
+       }
+       //write each normal clock wave for the clock duration
+       for (; i < clk; i+=waveLen){
+               memset(dest+(*n), *curPhase, halfWave);
+               memset(dest+(*n) + halfWave, *curPhase^1, halfWave);
+               *n += waveLen;
+       }
+}
+
+// args clock, carrier, invert,
+void CmdPSKsimTag(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
+{
+       int ledcontrol=1;
+       int n=0, i=0;
+       uint8_t clk = arg1 >> 8;
+       uint8_t carrier = arg1 & 0xFF;
+       uint8_t invert = arg2 & 0xFF;
+       uint8_t curPhase = 0;
+       for (i=0; i<size; i++){
+               if (BitStream[i] == curPhase){
+                       pskSimBit(carrier, &n, clk, &curPhase, FALSE);
+               } else {
+                       pskSimBit(carrier, &n, clk, &curPhase, TRUE);
+               }
+       }
+       Dbprintf("Simulating with Carrier: %d, clk: %d, invert: %d, n: %d",carrier, clk, invert, n);
+       //Dbprintf("DEBUG: First 32:");
+       //uint8_t *dest = BigBuf_get_addr();
+       //i=0;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       //i+=16;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+                  
+       if (ledcontrol) LED_A_ON();
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+       if (ledcontrol) LED_A_OFF();
+}
+
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
+void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       //const size_t sizeOfBigBuff = BigBuf_max_traceLen();
+       size_t size; 
+       uint32_t hi2=0, hi=0, lo=0;
+       int idx=0;
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition_default(-1,true);
+               // FSK demodulator
+               //size = sizeOfBigBuff;  //variable size will change after demod so re initialize it before use
+               size = 50*128*2; //big enough to catch 2 sequences of largest format
+               idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo);
+               
+               if (idx>0 && lo>0 && (size==96 || size==192)){
+                       // go over previously decoded manchester data and decode into usable tag ID
+                       if (hi2 != 0){ //extra large HID tags  88/192 bits
+                               Dbprintf("TAG ID: %x%08x%08x (%d)",
+                                 (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                       }else {  //standard HID tags 44/96 bits
+                               //Dbprintf("TAG ID: %x%08x (%d)",(unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF); //old print cmd
+                               uint8_t bitlen = 0;
+                               uint32_t fc = 0;
+                               uint32_t cardnum = 0;
+                               if (((hi>>5)&1) == 1){//if bit 38 is set then < 37 bit format is used
+                                       uint32_t lo2=0;
+                                       lo2=(((hi & 31) << 12) | (lo>>20)); //get bits 21-37 to check for format len bit
+                                       uint8_t idx3 = 1;
+                                       while(lo2 > 1){ //find last bit set to 1 (format len bit)
+                                               lo2=lo2 >> 1;
+                                               idx3++;
+                                       }
+                                       bitlen = idx3+19;
+                                       fc =0;
+                                       cardnum=0;
+                                       if(bitlen == 26){
+                                               cardnum = (lo>>1)&0xFFFF;
+                                               fc = (lo>>17)&0xFF;
+                                       }
+                                       if(bitlen == 37){
+                                               cardnum = (lo>>1)&0x7FFFF;
+                                               fc = ((hi&0xF)<<12)|(lo>>20);
+                                       }
+                                       if(bitlen == 34){
+                                               cardnum = (lo>>1)&0xFFFF;
+                                               fc= ((hi&1)<<15)|(lo>>17);
+                                       }
+                                       if(bitlen == 35){
+                                               cardnum = (lo>>1)&0xFFFFF;
+                                               fc = ((hi&1)<<11)|(lo>>21);
+                                       }
+                               }
+                               else { //if bit 38 is not set then 37 bit format is used
+                                       bitlen= 37;
+                                       fc =0;
+                                       cardnum=0;
+                                       if(bitlen==37){
+                                               cardnum = (lo>>1)&0x7FFFF;
+                                               fc = ((hi&0xF)<<12)|(lo>>20);
+                                       }
+                               }
+                               //Dbprintf("TAG ID: %x%08x (%d)",
+                               // (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                               Dbprintf("TAG ID: %x%08x (%d) - Format Len: %dbit - FC: %d - Card: %d",
+                                                (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF,
+                                                (unsigned int) bitlen, (unsigned int) fc, (unsigned int) cardnum);
+                       }
+                       if (findone){
+                               if (ledcontrol) LED_A_OFF();
+                               *high = hi;
+                               *low = lo;
+                               break;
+                       }
+                       // reset
+               }
+               hi2 = hi = lo = idx = 0;
+               WDT_HIT();
+       }
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
+void CmdAWIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       size_t size; 
+       int idx=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition_default(-1,true);
+               // FSK demodulator
+               size = 50*128*2; //big enough to catch 2 sequences of largest format
+               idx = AWIDdemodFSK(dest, &size);
+               
+               if (idx<=0 || size!=96) continue;
+               // Index map
+               // 0            10            20            30              40            50              60
+               // |            |             |             |               |             |               |
+               // 01234567 890 1 234 5 678 9 012 3 456 7 890 1 234 5 678 9 012 3 456 7 890 1 234 5 678 9 012 3 - to 96
+               // -----------------------------------------------------------------------------
+               // 00000001 000 1 110 1 101 1 011 1 101 1 010 0 000 1 000 1 010 0 001 0 110 1 100 0 000 1 000 1
+               // premable bbb o bbb o bbw o fff o fff o ffc o ccc o ccc o ccc o ccc o ccc o wxx o xxx o xxx o - to 96
+               //          |---26 bit---|    |-----117----||-------------142-------------|
+               // b = format bit len, o = odd parity of last 3 bits
+               // f = facility code, c = card number
+               // w = wiegand parity
+               // (26 bit format shown)
+
+               //get raw ID before removing parities
+               uint32_t rawLo = bytebits_to_byte(dest+idx+64,32);
+               uint32_t rawHi = bytebits_to_byte(dest+idx+32,32);
+               uint32_t rawHi2 = bytebits_to_byte(dest+idx,32);
+
+               size = removeParity(dest, idx+8, 4, 1, 88);
+               if (size != 66) continue;
+               // ok valid card found!
+
+               // Index map
+               // 0           10         20        30          40        50        60
+               // |           |          |         |           |         |         |
+               // 01234567 8 90123456 7890123456789012 3 456789012345678901234567890123456
+               // -----------------------------------------------------------------------------
+               // 00011010 1 01110101 0000000010001110 1 000000000000000000000000000000000
+               // bbbbbbbb w ffffffff cccccccccccccccc w xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+               // |26 bit|   |-117--| |-----142------|
+               // b = format bit len, o = odd parity of last 3 bits
+               // f = facility code, c = card number
+               // w = wiegand parity
+               // (26 bit format shown)
+
+               uint32_t fc = 0;
+               uint32_t cardnum = 0;
+               uint32_t code1 = 0;
+               uint32_t code2 = 0;
+               uint8_t fmtLen = bytebits_to_byte(dest,8);
+               if (fmtLen==26){
+                       fc = bytebits_to_byte(dest+9, 8);
+                       cardnum = bytebits_to_byte(dest+17, 16);
+                       code1 = bytebits_to_byte(dest+8,fmtLen);
+                       Dbprintf("AWID Found - BitLength: %d, FC: %d, Card: %d - Wiegand: %x, Raw: %08x%08x%08x", fmtLen, fc, cardnum, code1, rawHi2, rawHi, rawLo);
+               } else {
+                       cardnum = bytebits_to_byte(dest+8+(fmtLen-17), 16);
+                       if (fmtLen>32){
+                               code1 = bytebits_to_byte(dest+8,fmtLen-32);
+                               code2 = bytebits_to_byte(dest+8+(fmtLen-32),32);
+                               Dbprintf("AWID Found - BitLength: %d -unknown BitLength- (%d) - Wiegand: %x%08x, Raw: %08x%08x%08x", fmtLen, cardnum, code1, code2, rawHi2, rawHi, rawLo);
+                       } else{
+                               code1 = bytebits_to_byte(dest+8,fmtLen);
+                               Dbprintf("AWID Found - BitLength: %d -unknown BitLength- (%d) - Wiegand: %x, Raw: %08x%08x%08x", fmtLen, cardnum, code1, rawHi2, rawHi, rawLo);
+                       }
+               }
+               if (findone){
+                       if (ledcontrol) LED_A_OFF();
+                       break;
+               }
+               // reset
+               idx = 0;
+               WDT_HIT();
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+void CmdEM410xdemod(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+
+       size_t size=0, idx=0;
+       int clk=0, invert=0, errCnt=0, maxErr=20;
+       uint32_t hi=0;
+       uint64_t lo=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition_default(-1,true);
+               size  = BigBuf_max_traceLen();
+               //askdemod and manchester decode
+               if (size > 16385) size = 16385; //big enough to catch 2 sequences of largest format
+               errCnt = askdemod(dest, &size, &clk, &invert, maxErr, 0, 1);
+               WDT_HIT();
+
+               if (errCnt<0) continue;
+       
+               errCnt = Em410xDecode(dest, &size, &idx, &hi, &lo);
+               if (errCnt){
+                       if (size>64){
+                               Dbprintf("EM XL TAG ID: %06x%08x%08x - (%05d_%03d_%08d)",
+                                 hi,
+                                 (uint32_t)(lo>>32),
+                                 (uint32_t)lo,
+                                 (uint32_t)(lo&0xFFFF),
+                                 (uint32_t)((lo>>16LL) & 0xFF),
+                                 (uint32_t)(lo & 0xFFFFFF));
+                       } else {
+                               Dbprintf("EM TAG ID: %02x%08x - (%05d_%03d_%08d)",
+                                 (uint32_t)(lo>>32),
+                                 (uint32_t)lo,
+                                 (uint32_t)(lo&0xFFFF),
+                                 (uint32_t)((lo>>16LL) & 0xFF),
+                                 (uint32_t)(lo & 0xFFFFFF));
+                       }
+
+                       if (findone){
+                               if (ledcontrol) LED_A_OFF();
+                               *high=lo>>32;
+                               *low=lo & 0xFFFFFFFF;
+                               break;
+                       }
+               }
+               WDT_HIT();
+               hi = lo = size = idx = 0;
+               clk = invert = errCnt = 0;
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       int idx=0;
+       uint32_t code=0, code2=0;
+       uint8_t version=0;
+       uint8_t facilitycode=0;
+       uint16_t number=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+               DoAcquisition_default(-1,true);
+               //fskdemod and get start index
+               WDT_HIT();
+               idx = IOdemodFSK(dest, BigBuf_max_traceLen());
+               if (idx<0) continue;
+               //valid tag found
+
+               //Index map
+               //0           10          20          30          40          50          60
+               //|           |           |           |           |           |           |
+               //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+               //-----------------------------------------------------------------------------
+               //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+               //
+               //XSF(version)facility:codeone+codetwo
+               //Handle the data
+               if(findone){ //only print binary if we are doing one
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx],   dest[idx+1],   dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7],dest[idx+8]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15],dest[idx+16],dest[idx+17]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23],dest[idx+24],dest[idx+25],dest[idx+26]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+27],dest[idx+28],dest[idx+29],dest[idx+30],dest[idx+31],dest[idx+32],dest[idx+33],dest[idx+34],dest[idx+35]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+36],dest[idx+37],dest[idx+38],dest[idx+39],dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+45],dest[idx+46],dest[idx+47],dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d%d",dest[idx+54],dest[idx+55],dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
+               }
+               code = bytebits_to_byte(dest+idx,32);
+               code2 = bytebits_to_byte(dest+idx+32,32);
+               version = bytebits_to_byte(dest+idx+27,8); //14,4
+               facilitycode = bytebits_to_byte(dest+idx+18,8);
+               number = (bytebits_to_byte(dest+idx+36,8)<<8)|(bytebits_to_byte(dest+idx+45,8)); //36,9
+
+               Dbprintf("XSF(%02d)%02x:%05d (%08x%08x)",version,facilitycode,number,code,code2);
+               // if we're only looking for one tag
+               if (findone){
+                       if (ledcontrol) LED_A_OFF();
+                       //LED_A_OFF();
+                       *high=code;
+                       *low=code2;
+                       break;
+               }
+               code=code2=0;
+               version=facilitycode=0;
+               number=0;
+               idx=0;
+
+               WDT_HIT();
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+/*------------------------------
+ * T5555/T5557/T5567/T5577 routines
+ *------------------------------
+ * NOTE: T55x7/T5555 configuration register definitions moved to protocols.h
+ *
+ * Relevant communication times in microsecond
+ * To compensate antenna falling times shorten the write times
+ * and enlarge the gap ones.
+ * Q5 tags seems to have issues when these values changes. 
+ */
+#define START_GAP 31*8 // was 250 // SPEC:  1*8 to 50*8 - typ 15*8 (or 15fc)
+#define WRITE_GAP 20*8 // was 160 // SPEC:  1*8 to 20*8 - typ 10*8 (or 10fc)
+#define WRITE_0   18*8 // was 144 // SPEC: 16*8 to 32*8 - typ 24*8 (or 24fc)
+#define WRITE_1   50*8 // was 400 // SPEC: 48*8 to 64*8 - typ 56*8 (or 56fc)  432 for T55x7; 448 for E5550
+#define READ_GAP  15*8 
+
+void TurnReadLFOn(int delay) {
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+       // Give it a bit of time for the resonant antenna to settle.
+       SpinDelayUs(delay); //155*8 //50*8
+}
+
+// Write one bit to card
+void T55xxWriteBit(int bit) {
+       if (!bit)
+               TurnReadLFOn(WRITE_0);
+       else
+               TurnReadLFOn(WRITE_1);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelayUs(WRITE_GAP);
+}
+
+// Send T5577 reset command then read stream (see if we can identify the start of the stream)
+void T55xxResetRead(void) {
+       LED_A_ON();
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_keep_EM();
+
+       // Set up FPGA, 125kHz
+       LFSetupFPGAForADC(95, true);
+
+       // Trigger T55x7 in mode.
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelayUs(START_GAP);
+
+       // reset tag - op code 00
+       T55xxWriteBit(0);
+       T55xxWriteBit(0);
+
+       // Turn field on to read the response
+       TurnReadLFOn(READ_GAP);
+
+       // Acquisition
+       doT55x7Acquisition(BigBuf_max_traceLen());
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);    
+       LED_A_OFF();
+}
+
+// Write one card block in page 0, no lock
+void T55xxWriteBlockExt(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) {
+       LED_A_ON();
+       bool PwdMode = arg & 0x1;
+       uint8_t Page = (arg & 0x2)>>1;
+       uint32_t i = 0;
+
+       // Set up FPGA, 125kHz
+       LFSetupFPGAForADC(95, true);
+
+       // Trigger T55x7 in mode.
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelayUs(START_GAP);
+
+       // Opcode 10
+       T55xxWriteBit(1);
+       T55xxWriteBit(Page); //Page 0
+       if (PwdMode){
+               // Send Pwd
+               for (i = 0x80000000; i != 0; i >>= 1)
+                       T55xxWriteBit(Pwd & i);
+       }
+       // Send Lock bit
+       T55xxWriteBit(0);
+
+       // Send Data
+       for (i = 0x80000000; i != 0; i >>= 1)
+               T55xxWriteBit(Data & i);
+
+       // Send Block number
+       for (i = 0x04; i != 0; i >>= 1)
+               T55xxWriteBit(Block & i);
+
+       // Perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
+       // so wait a little more)
+       TurnReadLFOn(20 * 1000);
+               //could attempt to do a read to confirm write took
+               // as the tag should repeat back the new block 
+               // until it is reset, but to confirm it we would 
+               // need to know the current block 0 config mode
+
+       // turn field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       LED_A_OFF();
+}
+
+// Write one card block in page 0, no lock
+void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) {
+       T55xxWriteBlockExt(Data, Block, Pwd, arg);
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+// Read one card block in page [page]
+void T55xxReadBlock(uint16_t arg0, uint8_t Block, uint32_t Pwd) {
+       LED_A_ON();
+       bool PwdMode = arg0 & 0x1;
+       uint8_t Page = (arg0 & 0x2) >> 1;
+       uint32_t i = 0;
+       bool RegReadMode = (Block == 0xFF);
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       //make sure block is at max 7
+       Block &= 0x7;
+
+       // Set up FPGA, 125kHz to power up the tag
+       LFSetupFPGAForADC(95, true);
+
+       // Trigger T55x7 Direct Access Mode with start gap
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelayUs(START_GAP);
+
+       // Opcode 1[page]
+       T55xxWriteBit(1);
+       T55xxWriteBit(Page); //Page 0
+
+       if (PwdMode){
+               // Send Pwd
+               for (i = 0x80000000; i != 0; i >>= 1)
+                       T55xxWriteBit(Pwd & i);
+       }
+       // Send a zero bit separation
+       T55xxWriteBit(0);
+
+       // Send Block number (if direct access mode)
+       if (!RegReadMode)
+               for (i = 0x04; i != 0; i >>= 1)
+                       T55xxWriteBit(Block & i);               
+
+       // Turn field on to read the response
+       TurnReadLFOn(READ_GAP);
+
+       // Acquisition
+       doT55x7Acquisition(12000);
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);    
+       LED_A_OFF();
+}
+
+void T55xxWakeUp(uint32_t Pwd){
+       LED_B_ON();
+       uint32_t i = 0;
+       
+       // Set up FPGA, 125kHz
+       LFSetupFPGAForADC(95, true);
+       
+       // Trigger T55x7 Direct Access Mode
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       SpinDelayUs(START_GAP);
+       
+       // Opcode 10
+       T55xxWriteBit(1);
+       T55xxWriteBit(0); //Page 0
+
+       // Send Pwd
+       for (i = 0x80000000; i != 0; i >>= 1)
+               T55xxWriteBit(Pwd & i);
+
+       // Turn and leave field on to let the begin repeating transmission
+       TurnReadLFOn(20*1000);
+}
+
+/*-------------- Cloning routines -----------*/
+
+void WriteT55xx(uint32_t *blockdata, uint8_t startblock, uint8_t numblocks) {
+       // write last block first and config block last (if included)
+       for (uint8_t i = numblocks+startblock; i > startblock; i--) {
+               T55xxWriteBlockExt(blockdata[i-1],i-1,0,0);
+       }
+}
+
+// Copy HID id to card and setup block 0 config
+void CopyHIDtoT55x7(uint32_t hi2, uint32_t hi, uint32_t lo, uint8_t longFMT) {
+       uint32_t data[] = {0,0,0,0,0,0,0};
+       uint8_t last_block = 0;
+
+       if (longFMT) {
+               // Ensure no more than 84 bits supplied
+               if (hi2>0xFFFFF) {
+                       DbpString("Tags can only have 84 bits.");
+                       return;
+               }
+               // Build the 6 data blocks for supplied 84bit ID
+               last_block = 6;
+               // load preamble (1D) & long format identifier (9E manchester encoded)
+               data[1] = 0x1D96A900 | (manchesterEncode2Bytes((hi2 >> 16) & 0xF) & 0xFF);
+               // load raw id from hi2, hi, lo to data blocks (manchester encoded)
+               data[2] = manchesterEncode2Bytes(hi2 & 0xFFFF);
+               data[3] = manchesterEncode2Bytes(hi >> 16);
+               data[4] = manchesterEncode2Bytes(hi & 0xFFFF);
+               data[5] = manchesterEncode2Bytes(lo >> 16);
+               data[6] = manchesterEncode2Bytes(lo & 0xFFFF);
+       }       else {
+               // Ensure no more than 44 bits supplied
+               if (hi>0xFFF) {
+                       DbpString("Tags can only have 44 bits.");
+                       return;
+               }
+               // Build the 3 data blocks for supplied 44bit ID
+               last_block = 3;
+               // load preamble
+               data[1] = 0x1D000000 | (manchesterEncode2Bytes(hi) & 0xFFFFFF);
+               data[2] = manchesterEncode2Bytes(lo >> 16);
+               data[3] = manchesterEncode2Bytes(lo & 0xFFFF);
+       }
+       // load chip config block
+       data[0] = T55x7_BITRATE_RF_50 | T55x7_MODULATION_FSK2a | last_block << T55x7_MAXBLOCK_SHIFT;
+
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((50-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_FSK2 | T5555_INVERT_OUTPUT | last_block << T5555_MAXBLOCK_SHIFT;
+
+       LED_D_ON();
+       // Program the data blocks for supplied ID
+       // and the block 0 for HID format
+       WriteT55xx(data, 0, last_block+1);
+
+       LED_D_OFF();
+
+       DbpString("DONE!");
+}
+
+void CopyIOtoT55x7(uint32_t hi, uint32_t lo) {
+       uint32_t data[] = {T55x7_BITRATE_RF_64 | T55x7_MODULATION_FSK2a | (2 << T55x7_MAXBLOCK_SHIFT), hi, lo};
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((64-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_FSK2 | T5555_INVERT_OUTPUT | 2 << T5555_MAXBLOCK_SHIFT;
+
+       LED_D_ON();
+       // Program the data blocks for supplied ID
+       // and the block 0 config
+       WriteT55xx(data, 0, 3);
+
+       LED_D_OFF();
+
+       DbpString("DONE!");
+}
+
+// Clone Indala 64-bit tag by UID to T55x7
+void CopyIndala64toT55x7(uint32_t hi, uint32_t lo) {
+       //Program the 2 data blocks for supplied 64bit UID
+       // and the Config for Indala 64 format (RF/32;PSK1 with RF/2;Maxblock=2)
+       uint32_t data[] = { T55x7_BITRATE_RF_32 | T55x7_MODULATION_PSK1 | (2 << T55x7_MAXBLOCK_SHIFT), hi, lo};
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((32-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_PSK1 | 2 << T5555_MAXBLOCK_SHIFT;
+
+       WriteT55xx(data, 0, 3);
+       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=2;Inverse data)
+       //      T5567WriteBlock(0x603E1042,0);
+       DbpString("DONE!");
+}
+// Clone Indala 224-bit tag by UID to T55x7
+void CopyIndala224toT55x7(uint32_t uid1, uint32_t uid2, uint32_t uid3, uint32_t uid4, uint32_t uid5, uint32_t uid6, uint32_t uid7) {
+       //Program the 7 data blocks for supplied 224bit UID
+       uint32_t data[] = {0, uid1, uid2, uid3, uid4, uid5, uid6, uid7};
+       // and the block 0 for Indala224 format 
+       //Config for Indala (RF/32;PSK1 with RF/2;Maxblock=7)
+       data[0] = T55x7_BITRATE_RF_32 | T55x7_MODULATION_PSK1 | (7 << T55x7_MAXBLOCK_SHIFT);
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((32-2)>>1)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_PSK1 | 7 << T5555_MAXBLOCK_SHIFT;
+       WriteT55xx(data, 0, 8);
+       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=7;Inverse data)
+       //      T5567WriteBlock(0x603E10E2,0);
+       DbpString("DONE!");
+}
+// clone viking tag to T55xx
+void CopyVikingtoT55xx(uint32_t block1, uint32_t block2, uint8_t Q5) {
+       uint32_t data[] = {T55x7_BITRATE_RF_32 | T55x7_MODULATION_MANCHESTER | (2 << T55x7_MAXBLOCK_SHIFT), block1, block2};
+       if (Q5) data[0] = ( ((32-2)>>1) << T5555_BITRATE_SHIFT) | T5555_MODULATION_MANCHESTER | 2 << T5555_MAXBLOCK_SHIFT;
+       // Program the data blocks for supplied ID and the block 0 config
+       WriteT55xx(data, 0, 3);
+       LED_D_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+// Define 9bit header for EM410x tags
+#define EM410X_HEADER            0x1FF
+#define EM410X_ID_LENGTH       40
+
+void WriteEM410x(uint32_t card, uint32_t id_hi, uint32_t id_lo) {
+       int i, id_bit;
+       uint64_t id = EM410X_HEADER;
+       uint64_t rev_id = 0;    // reversed ID
+       int c_parity[4];        // column parity
+       int r_parity = 0;       // row parity
+       uint32_t clock = 0;
+
+       // Reverse ID bits given as parameter (for simpler operations)
+       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+               if (i < 32) {
+                       rev_id = (rev_id << 1) | (id_lo & 1);
+                       id_lo >>= 1;
+               } else {
+                       rev_id = (rev_id << 1) | (id_hi & 1);
+                       id_hi >>= 1;
+               }
+       }
+
+       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+               id_bit = rev_id & 1;
+
+               if (i % 4 == 0) {
+                       // Don't write row parity bit at start of parsing
+                       if (i)
+                               id = (id << 1) | r_parity;
+                       // Start counting parity for new row
+                       r_parity = id_bit;
+               } else {
+                       // Count row parity
+                       r_parity ^= id_bit;
+               }
+
+               // First elements in column?
+               if (i < 4)
+                       // Fill out first elements
+                       c_parity[i] = id_bit;
+               else
+                       // Count column parity
+                       c_parity[i % 4] ^= id_bit;
+
+               // Insert ID bit
+               id = (id << 1) | id_bit;
+               rev_id >>= 1;
+       }
+
+       // Insert parity bit of last row
+       id = (id << 1) | r_parity;
+
+       // Fill out column parity at the end of tag
+       for (i = 0; i < 4; ++i)
+               id = (id << 1) | c_parity[i];
+
+       // Add stop bit
+       id <<= 1;
+
+       Dbprintf("Started writing %s tag ...", card ? "T55x7":"T5555");
+       LED_D_ON();
+
+       // Write EM410x ID
+       uint32_t data[] = {0, (uint32_t)(id>>32), (uint32_t)(id & 0xFFFFFFFF)};
+
+       clock = (card & 0xFF00) >> 8;
+       clock = (clock == 0) ? 64 : clock;
+       Dbprintf("Clock rate: %d", clock);
+       if (card & 0xFF) { //t55x7
+               clock = GetT55xxClockBit(clock);                        
+               if (clock == 0) {
+                       Dbprintf("Invalid clock rate: %d", clock);
+                       return;
+               }
+               data[0] = clock | T55x7_MODULATION_MANCHESTER | (2 << T55x7_MAXBLOCK_SHIFT);
+       } else { //t5555 (Q5)
+               clock = (clock-2)>>1;  //n = (RF-2)/2
+               data[0] = (clock << T5555_BITRATE_SHIFT) | T5555_MODULATION_MANCHESTER | (2 << T5555_MAXBLOCK_SHIFT);
+       }
+
+       WriteT55xx(data, 0, 3);
+
+       LED_D_OFF();
+       Dbprintf("Tag %s written with 0x%08x%08x\n", card ? "T55x7":"T5555",
+                        (uint32_t)(id >> 32), (uint32_t)id);
+}
+
+//-----------------------------------
+// EM4469 / EM4305 routines
+//-----------------------------------
+#define FWD_CMD_LOGIN 0xC //including the even parity, binary mirrored
+#define FWD_CMD_WRITE 0xA
+#define FWD_CMD_READ 0x9
+#define FWD_CMD_DISABLE 0x5
+
+uint8_t forwardLink_data[64]; //array of forwarded bits
+uint8_t * forward_ptr; //ptr for forward message preparation
+uint8_t fwd_bit_sz; //forwardlink bit counter
+uint8_t * fwd_write_ptr; //forwardlink bit pointer
+
+//====================================================================
+// prepares command bits
+// see EM4469 spec
+//====================================================================
+//--------------------------------------------------------------------
+//  VALUES TAKEN FROM EM4x function: SendForward
+//  START_GAP = 440;       (55*8) cycles at 125Khz (8us = 1cycle)
+//  WRITE_GAP = 128;       (16*8)
+//  WRITE_1   = 256 32*8;  (32*8) 
+
+//  These timings work for 4469/4269/4305 (with the 55*8 above)
+//  WRITE_0 = 23*8 , 9*8  SpinDelayUs(23*8); 
+
+uint8_t Prepare_Cmd( uint8_t cmd ) {
+
+       *forward_ptr++ = 0; //start bit
+       *forward_ptr++ = 0; //second pause for 4050 code
+
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+
+       return 6; //return number of emited bits
+}
+
+//====================================================================
+// prepares address bits
+// see EM4469 spec
+//====================================================================
+uint8_t Prepare_Addr( uint8_t addr ) {
+
+       register uint8_t line_parity;
+
+       uint8_t i;
+       line_parity = 0;
+       for(i=0;i<6;i++) {
+               *forward_ptr++ = addr;
+               line_parity ^= addr;
+               addr >>= 1;
+       }
+
+       *forward_ptr++ = (line_parity & 1);
+
+       return 7; //return number of emited bits
+}
+
+//====================================================================
+// prepares data bits intreleaved with parity bits
+// see EM4469 spec
+//====================================================================
+uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
+
+       register uint8_t line_parity;
+       register uint8_t column_parity;
+       register uint8_t i, j;
+       register uint16_t data;
+
+       data = data_low;
+       column_parity = 0;
+
+       for(i=0; i<4; i++) {
+               line_parity = 0;
+               for(j=0; j<8; j++) {
+                       line_parity ^= data;
+                       column_parity ^= (data & 1) << j;
+                       *forward_ptr++ = data;
+                       data >>= 1;
+               }
+               *forward_ptr++ = line_parity;
+               if(i == 1)
+                       data = data_hi;
+       }
+
+       for(j=0; j<8; j++) {
+               *forward_ptr++ = column_parity;
+               column_parity >>= 1;
+       }
+       *forward_ptr = 0;
+
+       return 45; //return number of emited bits
+}
+
+//====================================================================
+// Forward Link send function
+// Requires: forwarLink_data filled with valid bits (1 bit per byte)
+// fwd_bit_count set with number of bits to be sent
+//====================================================================
+void SendForward(uint8_t fwd_bit_count) {
+
+       fwd_write_ptr = forwardLink_data;
+       fwd_bit_sz = fwd_bit_count;
+
+       // Set up FPGA, 125kHz
+       LFSetupFPGAForADC(95, true);
+
+       // force 1st mod pulse (start gap must be longer for 4305)
+       fwd_bit_sz--; //prepare next bit modulation
+       fwd_write_ptr++;
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       SpinDelayUs(56*8); //55 cycles off (8us each)for 4305  /another reader has 37 here...
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+       SpinDelayUs(18*8); //16 cycles on (8us each)  // another reader has 18 here
+
+       // now start writting
+       while(fwd_bit_sz-- > 0) { //prepare next bit modulation
+               if(((*fwd_write_ptr++) & 1) == 1)
+                       SpinDelayUs(32*8); //32 cycles at 125Khz (8us each)
+               else {
+                       //These timings work for 4469/4269/4305 (with the 55*8 above)
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+                       SpinDelayUs(23*8); //16-4 cycles off (8us each) //23  //one reader goes as high as 25 here
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+                       SpinDelayUs(16*8); //16 cycles on (8us each) //9  // another reader goes to 17 here
+               }
+       }
+}
+
+void EM4xLogin(uint32_t Password) {
+
+       uint8_t fwd_bit_count;
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
+       fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
+
+       SendForward(fwd_bit_count);
+
+       //Wait for command to complete
+       SpinDelay(20);
+}
+
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+       uint8_t fwd_bit_count;
+
+       // Clear destination buffer before sending the command
+       BigBuf_Clear_ext(false);
+
+       LED_A_ON();
+       //If password mode do login
+       if (PwdMode == 1) EM4xLogin(Pwd);
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
+       fwd_bit_count += Prepare_Addr( Address );
+
+       SendForward(fwd_bit_count);
+
+       // Now do the acquisition
+       doT55x7Acquisition(6000);
+       
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       LED_A_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+void EM4xWriteWord(uint32_t flag, uint32_t Data, uint32_t Pwd) {
+       
+       bool PwdMode = (flag & 0xF);
+       uint8_t Address = (flag >> 8) & 0xFF;
+       uint8_t fwd_bit_count;
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       LED_A_ON();
+       //If password mode do login
+       if (PwdMode) EM4xLogin(Pwd);
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
+       fwd_bit_count += Prepare_Addr( Address );
+       fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+       SendForward(fwd_bit_count);
+
+       //Wait for write to complete
+       SpinDelay(10);
+
+       //Capture response if one exists
+       DoAcquisition_default(20, TRUE);
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       LED_A_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+/*
+Reading a COTAG.
+
+COTAG needs the reader to send a startsequence and the card has an extreme slow datarate.
+because of this, we can "sample" the data signal but we interpreate it to Manchester direct.
+
+READER START SEQUENCE:
+burst 800 us,    gap   2.2 msecs
+burst 3.6 msecs  gap   2.2 msecs
+burst 800 us     gap   2.2 msecs
+pulse 3.6 msecs
+
+This triggers a COTAG tag to response
+*/
+void Cotag(uint32_t arg0) {
+
+#define OFF     { FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); WaitUS(2035); }
+#define ON(x)   { FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD); WaitUS((x)); }
+
+       uint8_t rawsignal = arg0 & 0xF;
+
+       LED_A_ON();
+
+       // Switching to LF image on FPGA. This might empty BigBuff
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       // Set up FPGA, 132kHz to power up the tag
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 89);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+       // Connect the A/D to the peak-detected low-frequency path.
+       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+       // Now set up the SSC to get the ADC samples that are now streaming at us.
+       FpgaSetupSsc();
+
+       // start clock - 1.5ticks is 1us
+       StartTicks();
+
+       //send COTAG start pulse
+       ON(740)  OFF
+       ON(3330) OFF
+       ON(740)  OFF
+       ON(1000)
+
+       switch(rawsignal) {
+               case 0: doCotagAcquisition(50000); break;
+               case 1: doCotagAcquisitionManchester(); break;
+               case 2: DoAcquisition_config(TRUE); break;
+       }
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);
+       LED_A_OFF();
+}
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