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fpga 14b merge p.N

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iceman1001 2020-07-14 15:46:05 +02:00
commit ce981d9124
1 changed files with 159 additions and 163 deletions
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310
armsrc/iso14443b.c
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@ -138,9 +138,9 @@ static uint32_t iso14b_timeout = TR0;
// them yet, just leaves them ready to send in ToSend[]. // them yet, just leaves them ready to send in ToSend[].
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
static void CodeIso14443bAsTag(const uint8_t *cmd, int len) { static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
int i; int i;
tosend_reset(); tosend_reset();
// Transmit a burst of ones, as the initial thing that lets the // Transmit a burst of ones, as the initial thing that lets the
// reader get phase sync. // reader get phase sync.
@ -152,56 +152,56 @@ static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
// Send TR1. // Send TR1.
// 10-11 ETU * 4times samples ONES // 10-11 ETU * 4times samples ONES
for (i = 0; i < 20; i++) { for (i = 0; i < 20; i++) {
SEND4STUFFBIT(1); SEND4STUFFBIT(1);
} }
// Send SOF. // Send SOF.
// 10-11 ETU * 4times samples ZEROS // 10-11 ETU * 4times samples ZEROS
for (i = 0; i < 10; i++) { for (i = 0; i < 10; i++) {
SEND4STUFFBIT(0); SEND4STUFFBIT(0);
} }
// 2-3 ETU * 4times samples ONES // 2-3 ETU * 4times samples ONES
for (i = 0; i < 2; i++) { for (i = 0; i < 2; i++) {
SEND4STUFFBIT(1); SEND4STUFFBIT(1);
} }
// data // data
for (i = 0; i < len; i++) { for (i = 0; i < len; i++) {
// Start bit // Start bit
SEND4STUFFBIT(0); SEND4STUFFBIT(0);
// Data bits // Data bits
uint8_t b = cmd[i]; uint8_t b = cmd[i];
for (int j = 0; j < 8; j++) { for (int j = 0; j < 8; j++) {
SEND4STUFFBIT(b & 1); SEND4STUFFBIT(b & 1);
b >>= 1; b >>= 1;
} }
// Stop bit // Stop bit
SEND4STUFFBIT(1); SEND4STUFFBIT(1);
// Extra Guard bit // Extra Guard bit
// For PICC it ranges 0-18us (1etu = 9us) // For PICC it ranges 0-18us (1etu = 9us)
//SEND4STUFFBIT(1); //SEND4STUFFBIT(1);
} }
// Send EOF. // Send EOF.
// 10-11 ETU * 4 sample rate = ZEROS // 10-11 ETU * 4 sample rate = ZEROS
for(i = 0; i < 10; i++) { for(i = 0; i < 10; i++) {
SEND4STUFFBIT(0); SEND4STUFFBIT(0);
} }
// why this? // why this?
for(i = 0; i < 2; i++) { for(i = 0; i < 2; i++) {
SEND4STUFFBIT(1); SEND4STUFFBIT(1);
} }
tosend_t *ts = get_tosend(); tosend_t *ts = get_tosend();
// Convert from last byte pos to length // Convert from last byte pos to length
ts->max++; ts->max++;
} }
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
@ -451,10 +451,10 @@ static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
while (BUTTON_PRESS() == false) { while (BUTTON_PRESS() == false) {
WDT_HIT(); WDT_HIT();
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
for (uint8_t mask = 0x80; mask != 0x00; mask >>= 1) { for (uint8_t mask = 0x80; mask != 0x00; mask >>= 1) {
if (Handle14443bReaderUartBit(b & mask)) { if (Handle14443bReaderUartBit(b & mask)) {
*len = Uart.byteCnt; *len = Uart.byteCnt;
return true; return true;
} }
@ -497,13 +497,13 @@ static void TransmitFor14443b_AsTag(uint8_t *response, uint16_t len) {
void SimulateIso14443bTag(uint32_t pupi) { void SimulateIso14443bTag(uint32_t pupi) {
LED_A_ON(); LED_A_ON();
// the only commands we understand is WUPB, AFI=0, Select All, N=1: // the only commands we understand is WUPB, AFI=0, Select All, N=1:
// static const uint8_t cmdWUPB[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB // static const uint8_t cmdWUPB[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB
// ... and REQB, AFI=0, Normal Request, N=1: // ... and REQB, AFI=0, Normal Request, N=1:
// static const uint8_t cmdREQB[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB // static const uint8_t cmdREQB[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB
// ... and HLTB // ... and HLTB
// static const uint8_t cmdHLTB[] = { 0x50, 0xff, 0xff, 0xff, 0xff }; // HLTB // static const uint8_t cmdHLTB[] = { 0x50, 0xff, 0xff, 0xff, 0xff }; // HLTB
// ... and ATTRIB // ... and ATTRIB
// static const uint8_t cmdATTRIB[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB // static const uint8_t cmdATTRIB[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
// ... if not PUPI/UID is supplied we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922, // ... if not PUPI/UID is supplied we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
@ -532,7 +532,7 @@ void SimulateIso14443bTag(uint32_t pupi) {
// connect Demodulated Signal to ADC: // connect Demodulated Signal to ADC:
SetAdcMuxFor(GPIO_MUXSEL_HIPKD); SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Set up the synchronous serial port // Set up the synchronous serial port
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR);
// allocate command receive buffer // allocate command receive buffer
@ -720,10 +720,7 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
} \ } \
} }
// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq) #define SUBCARRIER_DETECT_THRESHOLD 8
// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
#define SUBCARRIER_DETECT_THRESHOLD 8
//note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow //note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
#define CHECK_FOR_SUBCARRIER(void) { v = MAX(myI, myQ) + (MIN(myI, myQ) >> 1); } #define CHECK_FOR_SUBCARRIER(void) { v = MAX(myI, myQ) + (MIN(myI, myQ) >> 1); }
@ -773,8 +770,8 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
} else { } else {
// maximum length of TR1 = 200 1/fs // maximum length of TR1 = 200 1/fs
if (Demod.posCount > 200 / 4){ if (Demod.posCount > 200 / 4){
Demod.state = DEMOD_UNSYNCD; Demod.state = DEMOD_UNSYNCD;
} }
} }
Demod.posCount++; Demod.posCount++;
break; break;
@ -792,7 +789,7 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
LED_C_ON(); // Got SOF LED_C_ON(); // Got SOF
Demod.state = DEMOD_AWAITING_START_BIT; Demod.state = DEMOD_AWAITING_START_BIT;
Demod.posCount = 0; Demod.posCount = 0;
Demod.bitCount = 0; Demod.bitCount = 0;
Demod.len = 0; Demod.len = 0;
} }
} else { } else {
@ -811,12 +808,12 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
if (v > 0) { if (v > 0) {
if (Demod.posCount > 6 * 2) { // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs if (Demod.posCount > 6 * 2) { // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
LED_C_OFF(); LED_C_OFF();
if (Demod.bitCount == 0 && Demod.len == 0) { // received SOF only, this is valid for iClass/Picopass if (Demod.bitCount == 0 && Demod.len == 0) { // received SOF only, this is valid for iClass/Picopass
return true; return true;
} else { } else {
Demod.state = DEMOD_UNSYNCD; Demod.state = DEMOD_UNSYNCD;
} }
} }
} else { // start bit detected } else { // start bit detected
Demod.bitCount = 0; Demod.bitCount = 0;
@ -856,8 +853,8 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
// left shift to drop the startbit // left shift to drop the startbit
uint8_t b = (s >> 1); uint8_t b = (s >> 1);
Demod.output[Demod.len] = b; Demod.output[Demod.len] = b;
Demod.len++; Demod.len++;
Demod.bitCount = 0; Demod.bitCount = 0;
Demod.state = DEMOD_AWAITING_START_BIT; Demod.state = DEMOD_AWAITING_START_BIT;
} else { } else {
// this one is a bit hard, either its a correc byte or its unsynced. // this one is a bit hard, either its a correc byte or its unsynced.
@ -883,27 +880,26 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
/* /*
* Demodulate the samples we received from the tag, also log to tracebuffer * Demodulate the samples we received from the tag, also log to tracebuffer
* quiet: set to 'TRUE' to disable debug output
*/ */
static int GetTagSamplesFor14443bDemod(int timeout) { static int GetTagSamplesFor14443bDemod(int timeout) {
int ret = 0; int ret = 0;
int maxBehindBy = 0; int maxBehindBy = 0;
int lastRxCounter, samples = 0; int lastRxCounter, samples = 0;
int8_t ci, cq; int8_t ci, cq;
uint32_t time_0 = 0, time_stop = 0; uint32_t time_0 = 0, time_stop = 0;
BigBuf_free(); BigBuf_free();
// The response (tag -> reader) that we're receiving. // The response (tag -> reader) that we're receiving.
uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE); uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
// The DMA buffer, used to stream samples from the FPGA // The DMA buffer, used to stream samples from the FPGA
uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t)); uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t));
// Set up the demodulator for tag -> reader responses. // Set up the demodulator for tag -> reader responses.
Demod14bInit(receivedResponse); Demod14bInit(receivedResponse);
// wait for last transfer to complete // wait for last transfer to complete
while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)) while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY))
// Setup and start DMA. // Setup and start DMA.
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
@ -912,60 +908,60 @@ static int GetTagSamplesFor14443bDemod(int timeout) {
return -1; return -1;
} }
uint16_t *upTo = dmaBuf; uint16_t *upTo = dmaBuf;
lastRxCounter = ISO14443B_DMA_BUFFER_SIZE; lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
// Signal field is ON with the appropriate LED: // Signal field is ON with the appropriate LED:
LED_D_ON(); LED_D_ON();
// And put the FPGA in the appropriate mode // And put the FPGA in the appropriate mode
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_848_KHZ | FPGA_HF_READER_MODE_RECEIVE_IQ); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_848_KHZ | FPGA_HF_READER_MODE_RECEIVE_IQ);
for(;;) { for(;;) {
int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1); int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1);
if (behindBy > maxBehindBy) { if (behindBy > maxBehindBy) {
maxBehindBy = behindBy; maxBehindBy = behindBy;
} }
if (behindBy < 1) continue; if (behindBy < 1) continue;
ci = *upTo >> 8; ci = *upTo >> 8;
cq = *upTo; cq = *upTo;
upTo++; upTo++;
lastRxCounter--; lastRxCounter--;
if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dmaBuf; // start reading the circular buffer from the beginning upTo = dmaBuf; // start reading the circular buffer from the beginning
lastRxCounter += ISO14443B_DMA_BUFFER_SIZE; lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
} }
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated.
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers
} }
samples++; samples++;
if (Handle14443bTagSamplesDemod(ci, cq)) { if (Handle14443bTagSamplesDemod(ci, cq)) {
ret = Demod.len; ret = Demod.len;
break; break;
} }
if(samples > timeout && Demod.state < DEMOD_PHASE_REF_TRAINING) { if(samples > timeout && Demod.state < DEMOD_PHASE_REF_TRAINING) {
ret = -1; ret = -1;
LED_C_OFF(); LED_C_OFF();
break; break;
} }
} }
FpgaDisableSscDma(); FpgaDisableSscDma();
if (ret < 0) { if (ret < 0) {
return ret; return ret;
} }
if (Demod.len > 0) { if (Demod.len > 0) {
LogTrace(Demod.output, Demod.len, time_0, time_stop, NULL, false); LogTrace(Demod.output, Demod.len, time_0, time_stop, NULL, false);
} }
return ret; return ret;
} }
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
@ -973,27 +969,27 @@ static int GetTagSamplesFor14443bDemod(int timeout) {
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
static void TransmitFor14443b_AsReader(void) { static void TransmitFor14443b_AsReader(void) {
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_SHALLOW_MOD); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_SHALLOW_MOD);
LED_B_ON(); LED_B_ON();
tosend_t *ts = get_tosend(); tosend_t *ts = get_tosend();
for (int c = 0; c < ts->max; c++) { for (int c = 0; c < ts->max; c++) {
uint8_t data = ts->buf[c]; uint8_t data = ts->buf[c];
for (int i = 0; i < 8; i++) { for (int i = 0; i < 8; i++) {
uint16_t send_word = (data & 0x80) ? 0x0000 : 0xffff; uint16_t send_word = (data & 0x80) ? 0x0000 : 0xffff;
while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ; while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
AT91C_BASE_SSC->SSC_THR = send_word; AT91C_BASE_SSC->SSC_THR = send_word;
while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ; while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
AT91C_BASE_SSC->SSC_THR = send_word; AT91C_BASE_SSC->SSC_THR = send_word;
data <<= 1; data <<= 1;
} }
WDT_HIT(); WDT_HIT();
} }
LED_B_OFF(); LED_B_OFF();
} }
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
@ -1021,7 +1017,7 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len) {
// Send SOF // Send SOF
// 10-11 ETUs of ZERO // 10-11 ETUs of ZERO
for (int i = 0; i < 10; i++) for (int i = 0; i < 10; i++)
tosend_stuffbit(0); tosend_stuffbit(0);
// 2-3 ETUs of ONE // 2-3 ETUs of ONE
@ -1057,16 +1053,16 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len) {
// Send EOF // Send EOF
// 10-11 ETUs of ZERO // 10-11 ETUs of ZERO
for (int i = 0; i < 10; i++) for (int i = 0; i < 10; i++)
tosend_stuffbit(0); tosend_stuffbit(0);
// Transition time. TR0 - guard time // Transition time. TR0 - guard time
// 8ETUS minum? // 8ETUS minum?
// Per specification, Subcarrier must be stopped no later than 2 ETUs after EOF. // Per specification, Subcarrier must be stopped no later than 2 ETUs after EOF.
// I'm guessing this is for the FPGA to be able to send all bits before we switch to listening mode // I'm guessing this is for the FPGA to be able to send all bits before we switch to listening mode
// ensure that last byte is filled up // ensure that last byte is filled up
for (int i = 0; i < 8 ; ++i) for (int i = 0; i < 8 ; ++i)
tosend_stuffbit(1); tosend_stuffbit(1);
// TR1 - Synchronization time // TR1 - Synchronization time
// Convert from last character reference to length // Convert from last character reference to length
@ -1090,7 +1086,7 @@ static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len) {
* TODO: check CRC and preamble * TODO: check CRC and preamble
*/ */
uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response) { uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response) {
LED_A_ON(); LED_A_ON();
uint8_t message_frame[message_length + 4]; uint8_t message_frame[message_length + 4];
// PCB // PCB
message_frame[0] = 0x0A | pcb_blocknum; message_frame[0] = 0x0A | pcb_blocknum;
@ -1109,9 +1105,9 @@ uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *r
FpgaDisableTracing(); FpgaDisableTracing();
if (ret < 3) { if (ret < 3) {
LED_A_OFF(); LED_A_OFF();
return 0; return 0;
} }
// VALIDATE CRC // VALIDATE CRC
if (!check_crc(CRC_14443_B, Demod.output, Demod.len)) { if (!check_crc(CRC_14443_B, Demod.output, Demod.len)) {
@ -1123,7 +1119,7 @@ uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *r
memcpy(response, Demod.output, Demod.len); memcpy(response, Demod.output, Demod.len);
return Demod.len; return Demod.len;
LED_A_OFF(); LED_A_OFF();
} }
/** /**
@ -1280,7 +1276,7 @@ void iso14443b_setup(void) {
SetAdcMuxFor(GPIO_MUXSEL_HIPKD); SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Set up the synchronous serial port // Set up the synchronous serial port
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER); FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
// Signal field is on with the appropriate LED // Signal field is on with the appropriate LED
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_SHALLOW_MOD); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_SHALLOW_MOD);
@ -1439,15 +1435,15 @@ void RAMFUNC SniffIso14443b(void) {
iso1444b_setup_sniff(); iso1444b_setup_sniff();
// The DMA buffer, used to stream samples from the FPGA // The DMA buffer, used to stream samples from the FPGA
uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t)); uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t));
uint16_t *upTo = dmaBuf; uint16_t *upTo = dmaBuf;
int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE; int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
int8_t ci, cq; int8_t ci, cq;
int maxBehindBy = 0; int maxBehindBy = 0;
// Count of samples received so far, so that we can include timing // Count of samples received so far, so that we can include timing
// information in the trace buffer. // information in the trace buffer.
int samples = 0; int samples = 0;
// Setup and start DMA. // Setup and start DMA.
if (!FpgaSetupSscDma((uint8_t *) dmaBuf, ISO14443B_DMA_BUFFER_SIZE)) { if (!FpgaSetupSscDma((uint8_t *) dmaBuf, ISO14443B_DMA_BUFFER_SIZE)) {
@ -1462,38 +1458,38 @@ void RAMFUNC SniffIso14443b(void) {
// loop and listen // loop and listen
for(;;) { for(;;) {
int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE - 1); int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE - 1);
if (behindBy > maxBehindBy) { if (behindBy > maxBehindBy) {
maxBehindBy = behindBy; maxBehindBy = behindBy;
} }
if (behindBy < 1) continue; if (behindBy < 1) continue;
ci = *upTo >> 8; ci = *upTo >> 8;
cq = *upTo; cq = *upTo;
upTo++; upTo++;
lastRxCounter--; lastRxCounter--;
if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dmaBuf; // start reading the circular buffer from the beginning again upTo = dmaBuf; // start reading the circular buffer from the beginning again
lastRxCounter += ISO14443B_DMA_BUFFER_SIZE; lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
if (behindBy > (9 * ISO14443B_DMA_BUFFER_SIZE / 10)) { if (behindBy > (9 * ISO14443B_DMA_BUFFER_SIZE / 10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy); Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
break; break;
} }
} }
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated.
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers
WDT_HIT(); WDT_HIT();
if (BUTTON_PRESS()) { if (BUTTON_PRESS()) {
DbpString("Button pressed, cancelled"); DbpString("Button pressed, cancelled");
break; break;
} }
} }
samples++; samples++;
// no need to try decoding reader data if the tag is sending // no need to try decoding reader data if the tag is sending
if (TagIsActive == false) { if (TagIsActive == false) {
@ -1538,7 +1534,7 @@ void RAMFUNC SniffIso14443b(void) {
} }
} }
FpgaDisableSscDma(); FpgaDisableSscDma();
if (DBGLEVEL >= 2) { if (DBGLEVEL >= 2) {
DbpString("[+] Sniff statistics:"); DbpString("[+] Sniff statistics:");
Dbprintf("[+] uart State: %x ByteCount: %i ByteCountMax: %i", Uart.state, Uart.byteCnt, Uart.byteCntMax); Dbprintf("[+] uart State: %x ByteCount: %i ByteCountMax: %i", Uart.state, Uart.byteCnt, Uart.byteCntMax);