//static void GetSamplesFor14443(int weTx, int n);
-#define DEMOD_TRACE_SIZE 4096
+/*#define DEMOD_TRACE_SIZE 4096
#define READER_TAG_BUFFER_SIZE 2048
#define TAG_READER_BUFFER_SIZE 2048
#define DEMOD_DMA_BUFFER_SIZE 1024
-
+*/
//=============================================================================
// An ISO 14443 Type B tag. We listen for commands from the reader, using
// a UART kind of thing that's implemented in software. When we get a
return FALSE;
}
+static void DemodReset()
+{
+ // Clear out the state of the "UART" that receives from the tag.
+ Demod.output = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
+ Demod.len = 0;
+ Demod.state = DEMOD_UNSYNCD;
+ memset(Demod.output, 0x00, MAX_FRAME_SIZE);
+
+}
+
+static void UartReset()
+{
+ // And the UART that receives from the reader
+ Uart.output = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
+ Uart.byteCntMax = MAX_FRAME_SIZE;
+ Uart.state = STATE_UNSYNCD;
+}
+
/*
* Demodulate the samples we received from the tag, also log to tracebuffer
* weTx: set to 'TRUE' if we behave like a reader
int samples = 0;
- // Clear out the state of the "UART" that receives from the tag.
- memset(Demod.output, 0x00, MAX_FRAME_SIZE);
- Demod.output = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
- Demod.len = 0;
- Demod.state = DEMOD_UNSYNCD;
-
- // And the UART that receives from the reader
- Uart.output = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
- Uart.byteCntMax = MAX_FRAME_SIZE;
- Uart.state = STATE_UNSYNCD;
+ DemodReset();
+ UartReset();
// The DMA buffer, used to stream samples from the FPGA
int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
int8_t *upTo= dmaBuf;
- lastRxCounter = DEMOD_DMA_BUFFER_SIZE;
- FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE);
+ lastRxCounter = DMA_BUFFER_SIZE;
+ FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
// Signal field is ON with the appropriate LED:
if (weTx) LED_D_ON(); else LED_D_OFF();
int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
if(behindBy > max) max = behindBy;
- while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DEMOD_DMA_BUFFER_SIZE-1))
+ while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DMA_BUFFER_SIZE-1))
> 2)
{
ci = upTo[0];
cq = upTo[1];
upTo += 2;
- if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) {
- upTo -= DEMOD_DMA_BUFFER_SIZE;
+ if(upTo - dmaBuf > DMA_BUFFER_SIZE) {
+ upTo -= DMA_BUFFER_SIZE;
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
- AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
}
lastRxCounter -= 2;
if(lastRxCounter <= 0) {
- lastRxCounter += DEMOD_DMA_BUFFER_SIZE;
+ lastRxCounter += DMA_BUFFER_SIZE;
}
samples += 2;
int triggered = TRUE;
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
- // The command (reader -> tag) that we're working on receiving.
- uint8_t *receivedCmd = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE;
- // The response (tag -> reader) that we're working on receiving.
- uint8_t *receivedResponse = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE;
- // As we receive stuff, we copy it from receivedCmd or receivedResponse
- // into trace, along with its length and other annotations.
- uint8_t *trace = (uint8_t *)BigBuf;
- int traceLen = 0;
+ clear_trace();
+ set_tracing(TRUE);
+
+ // The command (reader -> tag) that we're receiving.
+ uint8_t *receivedCmd = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
+
+ // The response (tag -> reader) that we're receiving.
+ uint8_t *receivedResponse = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
// The DMA buffer, used to stream samples from the FPGA.
- int8_t *dmaBuf = (int8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE + TAG_READER_BUFFER_SIZE;
+ int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
int lastRxCounter;
int8_t *upTo;
int ci, cq;
// information in the trace buffer.
int samples = 0;
- // Initialize the trace buffer
- memset(trace, 0x44, DEMOD_TRACE_SIZE);
-
- // Set up the demodulator for tag -> reader responses.
- Demod.output = receivedResponse;
- Demod.len = 0;
- Demod.state = DEMOD_UNSYNCD;
-
- // And the reader -> tag commands
- memset(&Uart, 0, sizeof(Uart));
- Uart.output = receivedCmd;
- Uart.byteCntMax = 100;
- Uart.state = STATE_UNSYNCD;
+ DemodReset();
+ UartReset();
// Print some debug information about the buffer sizes
Dbprintf("Snooping buffers initialized:");
- Dbprintf(" Trace: %i bytes", DEMOD_TRACE_SIZE);
- Dbprintf(" Reader -> tag: %i bytes", READER_TAG_BUFFER_SIZE);
- Dbprintf(" tag -> Reader: %i bytes", TAG_READER_BUFFER_SIZE);
- Dbprintf(" DMA: %i bytes", DEMOD_DMA_BUFFER_SIZE);
+ Dbprintf(" Trace: %i bytes", TRACE_SIZE);
+ Dbprintf(" Reader -> tag: %i bytes", MAX_FRAME_SIZE);
+ Dbprintf(" tag -> Reader: %i bytes", MAX_FRAME_SIZE);
+ Dbprintf(" DMA: %i bytes", DMA_BUFFER_SIZE);
- // And put the FPGA in the appropriate mode
- // Signal field is off with the appropriate LED
- LED_D_OFF();
+ // Signal field is off with the appropriate LED
+ LED_D_OFF();
+
+ // And put the FPGA in the appropriate mode
FpgaWriteConfWord(
FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ |
FPGA_HF_READER_RX_XCORR_SNOOP);
// Setup for the DMA.
FpgaSetupSsc();
upTo = dmaBuf;
- lastRxCounter = DEMOD_DMA_BUFFER_SIZE;
- FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE);
-
+ lastRxCounter = DMA_BUFFER_SIZE;
+ FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
+ uint8_t parity[MAX_PARITY_SIZE];
LED_A_ON();
// And now we loop, receiving samples.
for(;;) {
int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
- (DEMOD_DMA_BUFFER_SIZE-1);
+ (DMA_BUFFER_SIZE-1);
if(behindBy > maxBehindBy) {
maxBehindBy = behindBy;
- if(behindBy > (DEMOD_DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not?
+ if(behindBy > (DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not?
Dbprintf("blew circular buffer! behindBy=0x%x", behindBy);
- goto done;
+ break;
}
}
if(behindBy < 2) continue;
cq = upTo[1];
upTo += 2;
lastRxCounter -= 2;
- if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) {
- upTo -= DEMOD_DMA_BUFFER_SIZE;
- lastRxCounter += DEMOD_DMA_BUFFER_SIZE;
+ if(upTo - dmaBuf > DMA_BUFFER_SIZE) {
+ upTo -= DMA_BUFFER_SIZE;
+ lastRxCounter += DMA_BUFFER_SIZE;
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
- AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
}
samples += 2;
-#define HANDLE_BIT_IF_BODY \
- if(triggered && tracing) {\
- uint8_t parity[MAX_PARITY_SIZE];\
- GetParity(receivedCmd, Uart.byteCnt, parity);\
- LogTrace(receivedCmd,Uart.byteCnt,samples, samples,parity,TRUE);\
- if(!tracing) {\
- DbpString("Reached trace limit");\
- break;\
- }\
- }\
- /* And ready to receive another command. */ \
- memset(&Uart, 0, sizeof(Uart)); \
- Uart.output = receivedCmd; \
- Uart.byteCntMax = 100; \
- Uart.state = STATE_UNSYNCD; \
- /* And also reset the demod code, which might have been */ \
- /* false-triggered by the commands from the reader. */ \
- memset(&Demod, 0, sizeof(Demod)); \
- Demod.output = receivedResponse; \
- Demod.state = DEMOD_UNSYNCD; \
-
if(Handle14443UartBit(ci & 1)) {
- HANDLE_BIT_IF_BODY
- }
+ if(triggered && tracing) {
+ GetParity(receivedCmd, Uart.byteCnt, parity);
+ LogTrace(receivedCmd,Uart.byteCnt,samples, samples,parity,TRUE);
+ }
+ /* And ready to receive another command. */
+ UartReset();
+ /* And also reset the demod code, which might have been */
+ /* false-triggered by the commands from the reader. */
+ DemodReset();
+ }
if(Handle14443UartBit(cq & 1)) {
- HANDLE_BIT_IF_BODY
- }
+ if(triggered && tracing) {
+ GetParity(receivedCmd, Uart.byteCnt, parity);
+ LogTrace(receivedCmd,Uart.byteCnt,samples, samples,parity,TRUE);
+ }
+ /* And ready to receive another command. */
+ UartReset();
+ /* And also reset the demod code, which might have been */
+ /* false-triggered by the commands from the reader. */
+ DemodReset();
+ }
if(Handle14443SamplesDemod(ci, cq)) {
uint8_t parity[MAX_PARITY_SIZE];
GetParity(receivedResponse, Demod.len, parity);
LogTrace(receivedResponse,Demod.len,samples, samples,parity,FALSE);
- if(!tracing) {
- DbpString("Reached trace limit");
- break;
- }
}
triggered = TRUE;
LED_A_OFF();
LED_B_ON();
// And ready to receive another response.
- memset(&Demod, 0, sizeof(Demod));
- Demod.output = receivedResponse;
- Demod.state = DEMOD_UNSYNCD;
+ DemodReset();
}
- WDT_HIT();
+ WDT_HIT();
+
+ if(!tracing) {
+ DbpString("Reached trace limit");
+ break;
+ }
if(BUTTON_PRESS()) {
DbpString("cancelled");
- goto done;
+ break;
}
}
-
-done:
+ FpgaDisableSscDma();
LED_A_OFF();
LED_B_OFF();
LED_C_OFF();
- AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
+ AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
DbpString("Snoop statistics:");
Dbprintf(" Max behind by: %i", maxBehindBy);
Dbprintf(" Uart State: %x", Uart.state);