AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(1) | SSC_CLOCK_MODE_START(1);
// 8 bits per transfer, no loopback, MSB first, 1 transfer per sync
- // pulse, no output sync, start on positive-going edge of sync
+ // pulse, no output sync
AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(8) | AT91C_SSC_MSBF | SSC_FRAME_MODE_WORDS_PER_TRANSFER(0);
// clock comes from TK pin, no clock output, outputs change on falling
- // edge of TK, start on rising edge of TF
+ // edge of TK, sample on rising edge of TK, start on positive-going edge of sync
AT91C_BASE_SSC->SSC_TCMR = SSC_CLOCK_MODE_SELECT(2) | SSC_CLOCK_MODE_START(5);
// tx framing is the same as the rx framing
return false;
}
- AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
- AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) buf;
- AT91C_BASE_PDC_SSC->PDC_RCR = len;
- AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) buf;
- AT91C_BASE_PDC_SSC->PDC_RNCR = len;
- AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTEN;
+ AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; // Disable DMA Transfer
+ AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) buf; // transfer to this memory address
+ AT91C_BASE_PDC_SSC->PDC_RCR = len; // transfer this many bytes
+ AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) buf; // next transfer to same memory address
+ AT91C_BASE_PDC_SSC->PDC_RNCR = len; // ... with same number of bytes
+ AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTEN; // go!
return true;
}