iso14444a: minor FPGA bugfix

[proxmark3-svn] / armsrc / fpgaloader.c

diff --git a/armsrc/fpgaloader.c b/armsrc/fpgaloader.c
index caf87ba987d12788ab39aa7ac04a725a3480a2a8..1e728e11884be4bbb438756266293be95325c757 100644 (file)
--- a/armsrc/fpgaloader.c
+++ b/armsrc/fpgaloader.c
@@ -116,13 +116,11 @@ void FpgaSetupSsc(void)
 
        // 8 bits per transfer, no loopback, MSB first, 1 transfer per sync
        // pulse, no output sync, start on positive-going edge of sync
-       AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(8) |
-               AT91C_SSC_MSBF | SSC_FRAME_MODE_WORDS_PER_TRANSFER(0);
+       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
-       AT91C_BASE_SSC->SSC_TCMR = SSC_CLOCK_MODE_SELECT(2) |
-               SSC_CLOCK_MODE_START(5);
+       // edge of TK, sample on rising edge of TK
+       AT91C_BASE_SSC->SSC_TCMR = SSC_CLOCK_MODE_SELECT(2) |   SSC_CLOCK_MODE_START(5);
 
        // tx framing is the same as the rx framing
        AT91C_BASE_SSC->SSC_TFMR = AT91C_BASE_SSC->SSC_RFMR;
@@ -136,13 +134,20 @@ void FpgaSetupSsc(void)
 // ourselves, not to another buffer). The stuff to manipulate those buffers
 // is in apps.h, because it should be inlined, for speed.
 //-----------------------------------------------------------------------------
-void FpgaSetupSscDma(uint8_t *buf, int len)
+bool FpgaSetupSscDma(uint8_t *buf, int len)
 {
-       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;
+       if (buf == NULL) {
+        return false;
+    }
+
+       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;
 }
 
 static void DownloadFPGA_byte(unsigned char w)