X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/644493821cc8053d97a6da425c398210ef6ebb1f..refs/pull/943/head:/armsrc/lfops.c diff --git a/armsrc/lfops.c b/armsrc/lfops.c index efa75652..995a8810 100644 --- a/armsrc/lfops.c +++ b/armsrc/lfops.c @@ -17,7 +17,7 @@ #include "lfdemod.h" #include "lfsampling.h" #include "protocols.h" -#include "usb_cdc.h" // for usb_poll_validate_length +#include "usb_cdc.h" #include "fpgaloader.h" /** @@ -1201,13 +1201,15 @@ void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol) /* // Original Timings for reference +//note startgap must be sent after tag has been powered up for more than 3ms (per T5557 ds) #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 +*/ /* Q5 timing datasheet: * Type | MIN | Typical | Max | * Start_Gap | 10*8 | ? | 50*8 | @@ -1241,15 +1243,6 @@ void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol) * Write_1 Fast Mode | 24*8 | 28*8 | 32*8 | */ -//note startgap must be sent after tag has been powered up for more than 3ms (per T5557 ds) -#define START_GAP 31*8 //31*8 // was 250 // SPEC: 1*8 to 50*8 - typ 15*8 (or 15fc) - T5557: 10*8 to 50*8 -#define WRITE_GAP 20*8 //20*8 // was 160 // SPEC: 1*8 to 20*8 - typ 10*8 (or 10fc) - T5557: 8*8 to 30*8 typ 50-150us -#define WRITE_0 18*8 //18*8 // was 144 // SPEC: 16*8 to 32*8 - typ 24*8 (or 24fc) - T5557: 16*8 to 31*8 typ 24*8 -#define WRITE_1 50*8 //50*8 // was 400 // SPEC: 48*8 to 64*8 - typ 56*8 (or 56fc) - T5557: 48*8 to 63*8 typ 54*8 432 for T55x7; 448 for E5550 - -#define READ_GAP 15*8 -*/ - // Structure to hold Timing values. In future will be simplier to add user changable timings. typedef struct { uint16_t START_GAP; @@ -1261,21 +1254,22 @@ typedef struct { uint16_t READ_GAP; } T55xx_Timing; - - // Set Initial/Default Values. Note: *8 can occure when used. This should keep things simplier here. T55xx_Timing T55xx_Timing_FixedBit = { 31 * 8 , 20 * 8 , 18 * 8 , 50 * 8 , 0 , 0 , 15 * 8 }; T55xx_Timing T55xx_Timing_LLR = { 31 * 8 , 20 * 8 , 18 * 8 , 50 * 8 , 0 , 0 , 15 * 8 }; T55xx_Timing T55xx_Timing_Leading0 = { 31 * 8 , 20 * 8 , 18 * 8 , 40 * 8 , 0 , 0 , 15 * 8 }; T55xx_Timing T55xx_Timing_1of4 = { 31 * 8 , 20 * 8 , 18 * 8 , 34 * 8 , 50 * 8 , 66 * 8 , 15 * 8 }; - // Some defines for readability -#define T55xx_LongLeadingReference 4 // Value to tell Write Bit to send long reference #define T55xx_DLMode_Fixed 0 // Default Mode #define T55xx_DLMode_LLR 1 // Long Leading Reference #define T55xx_DLMode_Leading0 2 // Leading Zero -#define T55xx_DLMode_1of4 3 // 1 of 4 +#define T55xx_DLMode_1of4 3 // 1 of 4 +#define T55xx_LongLeadingReference 4 // Value to tell Write Bit to send long reference +// Macro for code readability +#define BitStream_Byte(X) ((X) >> 3) +#define BitStream_Bit(X) ((X) & 7) + void TurnReadLFOn(int delay) { FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD); @@ -1287,19 +1281,18 @@ void TurnReadLFOn(int delay) { void T55xxWriteBit(int bit, T55xx_Timing *Timings) { // If bit = 4 Send Long Leading Reference which is 138 + WRITE_0 - + // Dbprintf ("Bits : %d",bit); switch (bit){ case 0 : TurnReadLFOn(Timings->WRITE_0); break; // Send bit 0/00 case 1 : TurnReadLFOn(Timings->WRITE_1); break; // Send bit 1/01 case 2 : TurnReadLFOn(Timings->WRITE_2); break; // Send bits 10 - case 3 : TurnReadLFOn(Timings->WRITE_3); break; // Send bits 11 - case 4 : TurnReadLFOn(Timings->WRITE_0 + (136 * 8)); break; // Send Long Leading Reference - } + case 3 : TurnReadLFOn(Timings->WRITE_3); break; // Send bits 11 + case 4 : TurnReadLFOn(Timings->WRITE_0 + (136 * 8)); break; // Send Long Leading Reference + } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); WaitUS(Timings->WRITE_GAP); } - // Function to abstract an Arbitrary length byte array to store bit pattern. // bit_array - Array to hold data/bit pattern // start_offset - bit location to start storing new bits. @@ -1307,148 +1300,113 @@ void T55xxWriteBit(int bit, T55xx_Timing *Timings) { // num_bits - how many bits (low x bits of data) Max 32 bits at a time // max_len - how many bytes can the bit_array hold (ensure no buffer overflow) // returns "Next" bit offset / bits stored (for next store) -int T55xx_SetBits (uint8_t *bit_array, int start_offset, uint32_t data , int num_bits, int max_len) +//int T55xx_SetBits (uint8_t *bit_array, int start_offset, uint32_t data , int num_bits, int max_len) +int T55xx_SetBits (uint8_t *BitStream, uint8_t start_offset, uint32_t data , uint8_t num_bits, uint8_t max_len) { - int bit,byte_idx, bit_idx; - int offset; - int NextOffset = start_offset; - - // Check if data will fit. - if ((start_offset + num_bits) <= (max_len*8)) { - - // Loop through the data and store - for (offset = (num_bits-1); offset >= 0; offset--) { - - bit = (data >> offset) & 1; // Get data bit value (0/1) - byte_idx = (NextOffset / 8); // Get Array Byte Index to Store - bit_idx = NextOffset - (byte_idx * 8); // Get Bit Index to set/clr - - // If set (1) we OR, if clear (0) we AND with inverse - // Dbprintf ("Add Bit : %d at byte %d bit %d",bit,byte_idx,bit_idx); - if (bit == 1) - bit_array[byte_idx] |= (1 << bit_idx); // Set the bit to 1 - - else - bit_array[byte_idx] &= (0xff ^ (1 << bit_idx)); // Set the bit to 0 (clr) - - NextOffset++; - } - } - else - Dbprintf ("Too Many Bits to fit into bit buffer"); - return NextOffset; -} + int8_t offset; + int8_t NextOffset = start_offset; -// 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(); + // Check if data will fit. + if ((start_offset + num_bits) <= (max_len*8)) { + // Loop through the data and store + for (offset = (num_bits-1); offset >= 0; offset--) { - // Set up FPGA, 125kHz - LFSetupFPGAForADC(95, true); - StartTicks(); - // make sure tag is fully powered up... - WaitMS(5); - - // Trigger T55x7 in mode. - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - WaitUS(T55xx_Timing_FixedBit.START_GAP); - - // reset tag - op code 00 - T55xxWriteBit(0,&T55xx_Timing_FixedBit); - T55xxWriteBit(0,&T55xx_Timing_FixedBit); - - TurnReadLFOn(T55xx_Timing_FixedBit.READ_GAP); + if ((data >> offset) & 1) BitStream[BitStream_Byte(NextOffset)] |= (1 << BitStream_Bit(NextOffset)); // Set the bit to 1 + else BitStream[BitStream_Byte(NextOffset)] &= (0xff ^ (1 << BitStream_Bit(NextOffset))); // Set the bit to 0 - // Acquisition - DoPartialAcquisition(0, true, BigBuf_max_traceLen(), 0); - - // Turn the field off - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off - cmd_send(CMD_ACK,0,0,0,0,0); - LED_A_OFF(); + NextOffset++; + } + } + else { + // Note: This should never happen unless some code changes cause it. + // So short message for coders when testing. + Dbprintf ("T55 too many bits"); + } + return NextOffset; } // Send one downlink command to the card -void T55xx_SendCMD (uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { //, bool read_cmd) {//, struct T55xx_Timing *Timing) { - +void T55xx_SendCMD (uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { + /* arg bits xxxxxxx1 0x01 PwdMode xxxxxx1x 0x02 Page xxxxx1xx 0x04 testMode xxx11xxx 0x18 downlink mode - xx1xxxxx 0x20 reg_readmode + xx1xxxxx 0x20 !reg_readmode x1xxxxxx 0x40 called for a read, so no data packet - + 1xxxxxxx 0x80 reset + */ - bool PwdMode = ((arg & 0x01) == 0x01); - uint8_t Page = (arg & 0x02) >> 1; - bool testMode = ((arg & 0x04) == 0x04); - uint8_t downlink_mode = (arg >> 3) & 0x03;; - bool reg_readmode = ((arg & 0x20) == 0x20); - bool read_cmd = ((arg & 0x40) == 0x40); - - int i = 0; - uint8_t BitStream[10]; // Max Downlink Command size ~75 bits, so 10 bytes (80 bits) + bool PwdMode = ((arg & 0x01) == 0x01); + bool Page = (arg & 0x02); + bool testMode = ((arg & 0x04) == 0x04); + uint8_t downlink_mode = (arg >> 3) & 0x03; + bool reg_readmode = ((arg & 0x20) == 0x20); + bool read_cmd = ((arg & 0x40) == 0x40); + bool reset = (arg & 0x80); + + uint8_t i = 0; + uint8_t BitStream[10]; // Max Downlink Command size ~74 bits, so 10 bytes (80 bits) uint8_t BitStreamLen; - int byte_idx, bit_idx; T55xx_Timing *Timing; - + uint8_t SendBits; // Assigning Downlink Timeing for write switch (downlink_mode) { case T55xx_DLMode_Fixed : Timing = &T55xx_Timing_FixedBit; break; - case T55xx_DLMode_LLR : Timing = &T55xx_Timing_LLR; break; + case T55xx_DLMode_LLR : Timing = &T55xx_Timing_LLR; break; case T55xx_DLMode_Leading0 : Timing = &T55xx_Timing_Leading0; break; case T55xx_DLMode_1of4 : Timing = &T55xx_Timing_1of4; break; default: Timing = &T55xx_Timing_FixedBit; - } + } // Build Bit Stream to send. memset (BitStream,0x00,sizeof(BitStream)); - BitStreamLen = 0; + BitStreamLen = 0; // Ensure 0 bit index to start. // Add Leading 0 and 1 of 4 reference bit - if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4)) + if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4)) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); // Add extra reference 0 for 1 of 4 - if (downlink_mode == T55xx_DLMode_1of4) + if (downlink_mode == T55xx_DLMode_1of4) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); - // Add Opcode - if (testMode) Dbprintf("TestMODE"); - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 0 : 1 , 1,sizeof(BitStream)); - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 1 : Page , 1,sizeof(BitStream)); - - if (PwdMode) { - - // Leading 0 and 1 of 4 00 fixed bits if passsword used - if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4)) { - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); - } - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Pwd, 32,sizeof(BitStream)); - + // Add Opcode + if (reset) { + // Reset : r*) 00 + BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 2,sizeof(BitStream)); } - // Add Lock bit - BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); + else + { + if (testMode) Dbprintf("TestMODE"); + BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 0 : 1 , 1,sizeof(BitStream)); + BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 1 : Page , 1,sizeof(BitStream)); + + if (PwdMode) { + // Leading 0 and 1 of 4 00 fixed bits if passsword used + if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4)) { + BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 2,sizeof(BitStream)); + } + BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Pwd, 32,sizeof(BitStream)); + } - // Add Data if a write command - if (!read_cmd) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Data, 32,sizeof(BitStream)); + // Add Lock bit 0 + if (!reg_readmode) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); - // Add Address - if (!reg_readmode) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Block, 3,sizeof(BitStream)); - + // Add Data if a write command + if (!read_cmd) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Data, 32,sizeof(BitStream)); + // Add Address + if (!reg_readmode) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Block, 3,sizeof(BitStream)); + } // Send Bits to T55xx - // Set up FPGA, 125kHz LFSetupFPGAForADC(95, true); StartTicks(); @@ -1458,35 +1416,49 @@ void T55xx_SendCMD (uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); WaitUS(Timing->START_GAP); - // If long leading 0 send long reference pulse if (downlink_mode == T55xx_DLMode_LLR) T55xxWriteBit (T55xx_LongLeadingReference,Timing); // Send Long Leading Start Reference - uint8_t SendBits; - - if (downlink_mode == T55xx_DLMode_1of4) { // 1 of 4 need to send 2 bits at a time - for (i = 0; i < BitStreamLen; i+=2) { - byte_idx = i / 8; - bit_idx = i - (byte_idx * 8); - SendBits = ((BitStream[byte_idx] >> bit_idx) & 1) << 1; - - byte_idx = (i+1) / 8; - bit_idx = (i+1) - (byte_idx * 8); - SendBits += (BitStream[byte_idx] >> bit_idx) & 1; - - T55xxWriteBit (SendBits,Timing); + if ((downlink_mode == T55xx_DLMode_1of4) && (BitStreamLen > 0)) { // 1 of 4 need to send 2 bits at a time + for ( i = 0; i < BitStreamLen-1; i+=2 ) { + SendBits = (BitStream[BitStream_Byte(i )] >> (BitStream_Bit(i )) & 1) << 1; // Bit i + SendBits += (BitStream[BitStream_Byte(i+1)] >> (BitStream_Bit(i+1)) & 1); // Bit i+1; + T55xxWriteBit (SendBits & 3,Timing); } } else { for (i = 0; i < BitStreamLen; i++) { - byte_idx = i / 8; - bit_idx = i - (byte_idx * 8); - SendBits = (BitStream[byte_idx] >> bit_idx) & 1; - T55xxWriteBit (SendBits,Timing); - } + SendBits = (BitStream[BitStream_Byte(i)] >> BitStream_Bit(i)); + T55xxWriteBit (SendBits & 1,Timing); + } } - +} + +// Send T5577 reset command then read stream (see if we can identify the start of the stream) +void T55xxResetRead(void) { + LED_A_ON(); + + // send r* 00 + uint8_t arg = 0x80; // SendCMD will add correct reference mode based on flags (when added). + + // Add in downlink_mode when ready + // arg |= 0x00; // dlmode << 3 (00 default - 08 leading 0 - 10 Fixed - 18 1 of 4 ) + + //clear buffer now so it does not interfere with timing later + BigBuf_Clear_keep_EM(); + + T55xx_SendCMD (0, 0, 0, arg); //, true); + + TurnReadLFOn(T55xx_Timing_FixedBit.READ_GAP); + + // Acquisition + DoPartialAcquisition(0, true, BigBuf_max_traceLen(), 0); + + // 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 @@ -1497,11 +1469,12 @@ void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { xxxxxx1x 0x02 Page xxxxx1xx 0x04 testMode xxx11xxx 0x18 downlink mode - xx1xxxxx 0x20 reg_readmode + xx1xxxxx 0x20 !reg_readmode x1xxxxxx 0x40 called for a read, so no data packet + 1xxxxxxx 0x80 reset */ - bool testMode = ((arg & 0x04) == 0x04); + bool testMode = ((arg & 0x04) == 0x04); arg &= (0xff ^ 0x40); // Called for a write, so ensure it is clear/0 LED_A_ON (); @@ -1536,7 +1509,7 @@ void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { } // turn field off FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - + cmd_send(CMD_ACK,0,0,0,0,0); LED_A_OFF (); @@ -1544,7 +1517,7 @@ void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { // Read one card block in page [page] void T55xxReadBlock (uint16_t arg0, uint8_t Block, uint32_t Pwd) {//, struct T55xx_Timing *Timing) { - + LED_A_ON(); /* @@ -1553,14 +1526,15 @@ void T55xxReadBlock (uint16_t arg0, uint8_t Block, uint32_t Pwd) {//, struct T55 xxxxxx1x 0x02 Page xxxxx1xx 0x04 testMode xxx11xxx 0x18 downlink mode - xx1xxxxx 0x20 reg_readmode + xx1xxxxx 0x20 !reg_readmode x1xxxxxx 0x40 called for a read, so no data packet + 1xxxxxxx 0x80 reset */ - + // Set Read Flag to ensure SendCMD does not add "data" to the packet arg0 |= 0x40; - + // RegRead Mode true of block 0xff if (Block == 0xff) arg0 |= 0x20; //make sure block is at max 7 @@ -1568,41 +1542,9 @@ void T55xxReadBlock (uint16_t arg0, uint8_t Block, uint32_t Pwd) {//, struct T55 //clear buffer now so it does not interfere with timing later BigBuf_Clear_ext(false); - - T55xx_SendCMD (0, Block, Pwd, arg0); //, true); - -/* -// the send has been moved to the above SendCMD Call -======= - - // Set up FPGA, 125kHz to power up the tag - LFSetupFPGAForADC(95, true); - StartTicks(); - // make sure tag is fully powered up... - WaitMS(5); - // Trigger T55x7 Direct Access Mode with start gap - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - WaitUS(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); + T55xx_SendCMD (0, Block, Pwd, arg0); //, true); -*/ // Turn field on to read the response // 137*8 seems to get to the start of data pretty well... // but we want to go past the start and let the repeating data settle in... @@ -1621,26 +1563,25 @@ void T55xxReadBlock (uint16_t arg0, uint8_t Block, uint32_t Pwd) {//, struct T55 void T55xxWakeUp(uint32_t Pwd){ LED_B_ON(); - uint32_t i = 0; - - // Set up FPGA, 125kHz - LFSetupFPGAForADC(95, true); - StartTicks(); - // make sure tag is fully powered up... - WaitMS(5); - - // Trigger T55x7 Direct Access Mode - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - WaitUS(T55xx_Timing_FixedBit.START_GAP); - - // Opcode 10 - T55xxWriteBit(1,&T55xx_Timing_FixedBit); - T55xxWriteBit(0,&T55xx_Timing_FixedBit); //Page 0 + /* + arg bits + xxxxxxx1 0x01 PwdMode + xxxxxx1x 0x02 Page + xxxxx1xx 0x04 testMode + xxx11xxx 0x18 downlink mode + xx1xxxxx 0x20 !reg_readmode + x1xxxxxx 0x40 called for a read, so no data packet + 1xxxxxxx 0x80 reset + */ - // Send Pwd - - for (i = 0x80000000; i != 0; i >>= 1) - T55xxWriteBit(Pwd & i,&T55xx_Timing_FixedBit); + // r* 10 (00) r* for llr , L0 and 1/4 - (00) for L0 and 1/4 - All handled in SendCMD + // So, default Opcode 10 and pwd. + uint8_t arg = 0x01 | 0x40 | 0x20; //Password Read Call no data | reg_read no block + + // Add in downlink_mode when ready + // arg |= 0x00; // dlmode << 3 (00 default - 08 leading 0 - 10 Fixed - 18 1 of 4 ) + + T55xx_SendCMD (0, 0, Pwd, arg); //, true); // Turn and leave field on to let the begin repeating transmission TurnReadLFOn(20*1000); @@ -1651,8 +1592,8 @@ void T55xxWakeUp(uint32_t Pwd){ 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--) { - T55xxWriteBlock(blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit); - // T55xx_SendCMD (blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit); + T55xxWriteBlock(blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit); + //T55xx_SendCMD (blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit); } } @@ -1966,7 +1907,7 @@ void SendForward(uint8_t fwd_bit_count) { FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on WaitUS(18*8); //18 cycles on (8us each) - // now start writting + // now start writting - each bit should be 32*8 total length while(fwd_bit_sz-- > 0) { //prepare next bit modulation if(((*fwd_write_ptr++) & 1) == 1) WaitUS(32*8); //32 cycles at 125Khz (8us each) @@ -1975,7 +1916,7 @@ void SendForward(uint8_t fwd_bit_count) { FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off WaitUS(23*8); //23 cycles off (8us each) FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on - WaitUS(18*8); //18 cycles on (8us each) + WaitUS((32-23)*8); //remaining cycles on (8us each) } } }