Diff: dma.cpp

Revision:

51:43143a3fc2d7

Parent:

50:33524a27e08c

--- a/dma.cpp	Sat Jan 31 19:46:00 2015 +0000
+++ b/dma.cpp	Sat Jan 31 20:17:58 2015 +0000
@@ -8,9 +8,12 @@
 uint16_t sample_array0[TOTAL_SAMPLES];
 uint16_t sample_array1[TOTAL_SAMPLES];
 uint16_t angle_array[TOTAL_SAMPLES];
-//DigitalIn AMT20_A(PTB18); // FTM2_QD_PHA, apparently the k64f has a quadrature decoder.  look into this (page 264)
-//DigitalIn AMT20_B(PTB10); // FTM2_QD_PHB
+
+
 
+/*  DMA0 and DMA1 are triggered by ADC0 and ADC1 (which are triggered
+ *  by the PDB).  However, DMA2 is triggered directly by the PDB.  This
+ *  is becuase DMA2 is reading FTM2, which cannot trigger the DMA.   */
 void dma_init()
 {
     // Enable clock for DMAMUX and DMA
@@ -22,12 +25,10 @@
     DMAMUX_CHCFG0 |= DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(40); // ADC0
     DMAMUX_CHCFG1 |= DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(41); // ADC1
     DMAMUX_CHCFG2 |= DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(48); // Set trigger source to PDB (Don't set DMA Trig Enable because that is for the PIT)
-    /* Source number    Source module    Source description
+    /* Source number    Source module
            40                ADC0
            41                ADC1
-           30                FTM2             Channel 0
-           31                FTM2             Channel 1
-           48                PDB                  -
+           48                PDB
     */
     
     
@@ -85,9 +86,17 @@
     DMA_TCD0_CSR = 0;
     DMA_TCD1_CSR = 0;
     DMA_TCD2_CSR = 0;
-    
-    
-    /*pc.printf("DMA_CR: %08x\r\n", DMA_CR);
+}
+
+void dma_reset() {
+    // Set memory address for destinations back to the beginning
+    dma_init();
+}
+
+
+
+
+/*pc.printf("DMA_CR: %08x\r\n", DMA_CR);
     pc.printf("DMA_ES: %08x\r\n", DMA_ES);
     pc.printf("DMA_ERQ: %08x\r\n", DMA_ERQ);
     pc.printf("DMA_EEI: %08x\r\n", DMA_EEI);
@@ -101,10 +110,4 @@
     pc.printf("DMA_CINT: %02x\r\n", DMA_CINT);
     pc.printf("DMA_INT: %08x\r\n", DMA_INT);
     pc.printf("DMA_ERR: %08x\r\n", DMA_ERR);
-    pc.printf("DMA_HRS: %08x\r\n", DMA_HRS);*/
-}
-
-void dma_reset() {
-    // Set memory address for destinations back to the beginning
-    dma_init();
-}
+    pc.printf("DMA_HRS: %08x\r\n", DMA_HRS);*/
\ No newline at end of file