-void pushBit( BitstreamOut* stream, uint8_t bit)
-{
- int bytepos = stream->position >> 3; // divide by 8
- int bitpos = stream->position & 7;
- *(stream->buffer+bytepos) |= (bit > 0) << (7 - bitpos);
- stream->position++;
- stream->numbits++;
-}
-
-/**
- * Does the sample acquisition. If threshold is specified, the actual sampling
- * is not commenced until the threshold has been reached.
- * This method implements decimation and quantization in order to
- * be able to provide longer sample traces.
- * Uses the following global settings:
- * - decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
- * - bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
- * - averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
- * value that will be used is the average value of the three samples.
- *
- * @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
- * to -1 to ignore threshold.
- * @param silent - is true, now outputs are made. If false, dbprints the status
- * @return the number of bits occupied by the samples.
- */
-uint32_t DoAcquisition125k_internal(int trigger_threshold,bool silent)
-{
- //.
- uint8_t *dest = (uint8_t *)BigBuf;
- int bufsize = BIGBUF_SIZE;
- memset(dest, 0, bufsize);
-
- if(bits_per_sample < 1) bits_per_sample = 1;
- if(bits_per_sample > 8) bits_per_sample = 8;
-
- if(decimation < 1) decimation = 1;
-
- // Use a bit stream to handle the output
- BitstreamOut data = { dest , 0, 0};
- int sample_counter = 0;
- uint8_t sample = 0;
- //If we want to do averaging
- uint32_t sample_sum =0 ;
- uint32_t sample_total_numbers =0 ;
- uint32_t sample_total_saved =0 ;
-
- while(!BUTTON_PRESS()) {
- WDT_HIT();
- if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
- AT91C_BASE_SSC->SSC_THR = 0x43;
- LED_D_ON();
- }
- if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
- sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- LED_D_OFF();
- if (trigger_threshold != -1 && sample < trigger_threshold)
- continue;
-
- trigger_threshold = -1;
- sample_total_numbers++;
-
- if(averaging)
- {
- sample_sum += sample;
- }
- //Check decimation
- if(decimation > 1)
- {
- sample_counter++;
- if(sample_counter < decimation) continue;
- sample_counter = 0;
- }
- //Averaging
- if(averaging && decimation > 1) {
- sample = sample_sum / decimation;
- sample_sum =0;
- }
- //Store the sample
- sample_total_saved ++;
- if(bits_per_sample == 8){
- dest[sample_total_saved-1] = sample;
- data.numbits = sample_total_saved << 3;//Get the return value correct
- if(sample_total_saved >= bufsize) break;
- }
- else{
- pushBit(&data, sample & 0x80);
- if(bits_per_sample > 1) pushBit(&data, sample & 0x40);
- if(bits_per_sample > 2) pushBit(&data, sample & 0x20);
- if(bits_per_sample > 3) pushBit(&data, sample & 0x10);
- if(bits_per_sample > 4) pushBit(&data, sample & 0x08);
- if(bits_per_sample > 5) pushBit(&data, sample & 0x04);
- if(bits_per_sample > 6) pushBit(&data, sample & 0x02);
- //Not needed, 8bps is covered above
- //if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
- if((data.numbits >> 3) +1 >= bufsize) break;
- }
- }
- }
-
- if(!silent)
- {
- Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved, sample_total_numbers,bits_per_sample);
- Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
- dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
- }
- return data.numbits;
-}
-/**
-* Perform sample aquisition.
-*/
-void DoAcquisition125k(int trigger_threshold)
-{
- DoAcquisition125k_internal(trigger_threshold, false);
-}
-
-/**
-* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
-* if not already loaded, sets divisor and starts up the antenna.
-* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
-* 0 or 95 ==> 125 KHz
-*
-**/
-void LFSetupFPGAForADC(int divisor, bool lf_field)
-{
- FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
- if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
- else if (divisor == 0)
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- else
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
-
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
-
- // Connect the A/D to the peak-detected low-frequency path.
- SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
- // Give it a bit of time for the resonant antenna to settle.
- SpinDelay(50);
- // Now set up the SSC to get the ADC samples that are now streaming at us.
- FpgaSetupSsc();
-}
-/**
-* Initializes the FPGA, and acquires the samples.
-**/
-void AcquireRawAdcSamples125k(int divisor,int arg1, int arg2)
-{
- if (arg1 != 0)
- {
- averaging = (arg1 & 0x80) != 0;
- bits_per_sample = (arg1 & 0x0F);
- }
- if(arg2 != 0)
- {
- decimation = arg2;
- }
-
- Dbprintf("Sampling config: ");
- Dbprintf(" divisor: %d ", divisor);
- Dbprintf(" bps: %d ", bits_per_sample);
- Dbprintf(" decimation: %d ", decimation);
- Dbprintf(" averaging: %d ", averaging);
-
- LFSetupFPGAForADC(divisor, true);
- // Now call the acquisition routine
- DoAcquisition125k_internal(-1,false);
-}
-/**
-* Initializes the FPGA for snoop-mode, and acquires the samples.
-**/
-
-void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
-{
- LFSetupFPGAForADC(divisor, false);
- DoAcquisition125k(trigger_threshold);
-}
-
projects / proxmark3-svn / blobdiff