#define DELAY_READER_TO_ARM 8
#define DELAY_ARM_TO_READER 0
//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when acting as reader. All values should be multiples of 16
-#define DELAY_TAG_TO_ARM 32
#define DELAY_ARM_TO_TAG 16
+#define DELAY_TAG_TO_ARM 32
+//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when snooping. All values should be multiples of 16
+#define DELAY_TAG_TO_ARM_SNOOP 32
+#define DELAY_READER_TO_ARM_SNOOP 32
static int DEBUG = 0;
*start_time = (*start_time - DELAY_ARM_TO_TAG) & 0xfffffff0;
- while (GetCountSspClk() > *start_time) { // we may miss the intended time
- *start_time += 16; // next possible time
+ if (GetCountSspClk() > *start_time) { // we may miss the intended time
+ *start_time = (GetCountSspClk() + 16) & 0xfffffff0; // next possible time
}
-
while (GetCountSspClk() < *start_time)
/* wait */ ;
} DecodeTag_t;
-static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag)
-{
+static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag) {
switch(DecodeTag->state) {
case STATE_TAG_SOF_LOW:
// waiting for a rising edge
if (amplitude > NOISE_THRESHOLD + DecodeTag->previous_amplitude) {
if (DecodeTag->posCount > 10) {
- DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude;
+ DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude; // to be divided by 2
DecodeTag->threshold_half = 0;
DecodeTag->state = STATE_TAG_SOF_RISING_EDGE;
} else {
break;
case STATE_TAG_SOF_RISING_EDGE:
- if (amplitude - DecodeTag->previous_amplitude > DecodeTag->threshold_sof) { // edge still rising
- if (amplitude - DecodeTag->threshold_sof > DecodeTag->threshold_sof) { // steeper edge, take this as time reference
+ if (amplitude > DecodeTag->threshold_sof + DecodeTag->previous_amplitude) { // edge still rising
+ if (amplitude > DecodeTag->threshold_sof + DecodeTag->threshold_sof) { // steeper edge, take this as time reference
DecodeTag->posCount = 1;
} else {
DecodeTag->posCount = 2;
DecodeTag->sum2 = 0;
DecodeTag->posCount = 2;
DecodeTag->state = STATE_TAG_RECEIVING_DATA;
- FpgaDisableTracing(); // DEBUGGING
- Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
- amplitude,
- DecodeTag->threshold_sof,
- DecodeTag->threshold_half/4,
- DecodeTag->previous_amplitude); // DEBUGGING
+ // FpgaDisableTracing(); // DEBUGGING
+ // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
+ // amplitude,
+ // DecodeTag->threshold_sof,
+ // DecodeTag->threshold_half/4,
+ // DecodeTag->previous_amplitude); // DEBUGGING
LED_C_ON();
} else {
DecodeTag->posCount++;
break;
case STATE_TAG_RECEIVING_DATA:
+ // FpgaDisableTracing(); // DEBUGGING
+ // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
+ // amplitude,
+ // DecodeTag->threshold_sof,
+ // DecodeTag->threshold_half/4,
+ // DecodeTag->previous_amplitude); // DEBUGGING
if (DecodeTag->posCount == 1) {
DecodeTag->sum1 = 0;
DecodeTag->sum2 = 0;
if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dmaBuf; // start reading the circular buffer from the beginning
- if(behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+ if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
ret = -1;
break;
}
-void SnoopIso15693(void)
-{
+void SnoopIso15693(void) {
+
LED_A_ON();
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
- BigBuf_free();
clear_trace();
set_tracing(true);
// The DMA buffer, used to stream samples from the FPGA
- uint16_t* dmaBuf = (uint16_t*)BigBuf_malloc(ISO15693_DMA_BUFFER_SIZE*sizeof(uint16_t));
- uint16_t *upTo;
+ uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE];
// Count of samples received so far, so that we can include timing
// information in the trace buffer.
Dbprintf("Snoop started. Press PM3 Button to stop.");
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE);
+ LED_D_OFF();
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
- // Setup for the DMA.
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
- upTo = dmaBuf;
+ StartCountSspClk();
FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
-
+
bool TagIsActive = false;
bool ReaderIsActive = false;
bool ExpectTagAnswer = false;
-
+ uint32_t dma_start_time = 0;
+ uint16_t *upTo = dmaBuf;
+
// And now we loop, receiving samples.
for(;;) {
uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1);
if (behindBy == 0) continue;
+ samples++;
+ if (samples == 1) {
+ // DMA has transferred the very first data
+ dma_start_time = GetCountSspClk() & 0xfffffff0;
+ }
+
uint16_t snoopdata = *upTo++;
- if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
+ if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dmaBuf; // start reading the circular buffer from the beginning
- if(behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+ if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy=%d, samples=%d", behindBy, samples);
break;
}
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE; // DMA Next Counter registers
WDT_HIT();
- if(BUTTON_PRESS()) {
+ if (BUTTON_PRESS()) {
DbpString("Snoop stopped.");
break;
}
}
}
- samples++;
if (!TagIsActive) { // no need to try decoding reader data if the tag is sending
if (Handle15693SampleFromReader(snoopdata & 0x02, &DecodeReader)) {
- FpgaDisableSscDma();
- ExpectTagAnswer = true;
- LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, samples*64, samples*64, NULL, true);
+ // FpgaDisableSscDma();
+ uint32_t eof_time = dma_start_time + samples*16 + 8 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+ if (DecodeReader.byteCount > 0) {
+ uint32_t sof_time = eof_time
+ - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+ - 32*16 // time for SOF transfer
+ - 16*16; // time for EOF transfer
+ LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+ }
/* And ready to receive another command. */
DecodeReaderReset(&DecodeReader);
/* And also reset the demod code, which might have been */
/* false-triggered by the commands from the reader. */
DecodeTagReset(&DecodeTag);
- upTo = dmaBuf;
- FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
- }
- if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) {
- FpgaDisableSscDma();
+ ReaderIsActive = false;
ExpectTagAnswer = true;
- LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, samples*64, samples*64, NULL, true);
+ // upTo = dmaBuf;
+ // samples = 0;
+ // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+ // continue;
+ } else if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) {
+ // FpgaDisableSscDma();
+ uint32_t eof_time = dma_start_time + samples*16 + 16 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+ if (DecodeReader.byteCount > 0) {
+ uint32_t sof_time = eof_time
+ - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+ - 32*16 // time for SOF transfer
+ - 16*16; // time for EOF transfer
+ LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+ }
/* And ready to receive another command. */
DecodeReaderReset(&DecodeReader);
/* And also reset the demod code, which might have been */
/* false-triggered by the commands from the reader. */
DecodeTagReset(&DecodeTag);
- upTo = dmaBuf;
- FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+ ReaderIsActive = false;
+ ExpectTagAnswer = true;
+ // upTo = dmaBuf;
+ // samples = 0;
+ // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+ // continue;
+ } else {
+ ReaderIsActive = (DecodeReader.state >= STATE_READER_RECEIVE_DATA_1_OUT_OF_4);
}
- ReaderIsActive = (DecodeReader.state >= STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF);
}
if (!ReaderIsActive && ExpectTagAnswer) { // no need to try decoding tag data if the reader is currently sending or no answer expected yet
if (Handle15693SamplesFromTag(snoopdata >> 2, &DecodeTag)) {
- FpgaDisableSscDma();
- //Use samples as a time measurement
- LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, samples*64, samples*64, NULL, false);
+ // FpgaDisableSscDma();
+ uint32_t eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM_SNOOP; // end of EOF
+ if (DecodeTag.lastBit == SOF_PART2) {
+ eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS)
+ }
+ uint32_t sof_time = eof_time
+ - DecodeTag.len * 8 * 8 * 16 // time for byte transfers
+ - 32 * 16 // time for SOF transfer
+ - (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer
+ LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, eof_time*4, NULL, false);
// And ready to receive another response.
DecodeTagReset(&DecodeTag);
DecodeReaderReset(&DecodeReader);
ExpectTagAnswer = false;
- upTo = dmaBuf;
- FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+ TagIsActive = false;
+ // upTo = dmaBuf;
+ // samples = 0;
+ // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+ // continue;
+ } else {
+ TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
}
- TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
}
}
FpgaDisableSscDma();
- BigBuf_free();
LEDsoff();
projects / proxmark3-svn / blobdiff