Kevin Tseng / MODDMA

Test

Dependents:   DSHOT_test

example3.h@18:e7d62a489a83, 2019-04-25 (annotated)

Committer:
ktseng
Date:
Thu Apr 25 19:20:22 2019 +0000
Revision:
18:e7d62a489a83
Parent:
16:cb10aec6feb1 
Test;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AjK 12:1dfee7208043 1 /*
AjK 12:1dfee7208043 2 * Demonstrates capturing the GPIO P0.4 to P0.7 "nibble" to memory
AjK 12:1dfee7208043 3 * using GPDMA. The transfers from port pins to memory buffer are
AjK 12:1dfee7208043 4 * triggered using Timer1 MAT1.0 match compare.
AjK 12:1dfee7208043 5 *
AjK 12:1dfee7208043 6 * In this example all inputs have pullups. So with nothing connected
AjK 12:1dfee7208043 7 * the P0.4/7 reads as 0xF. Connecting a wire from one or more of the four
AjK 12:1dfee7208043 8 * inputs to ground will show up in the captured buffer sequence.
AjK 12:1dfee7208043 9 */
AjK 12:1dfee7208043 10
AjK 12:1dfee7208043 11 #include "mbed.h"
AjK 12:1dfee7208043 12 #include "MODDMA.h"
AjK 12:1dfee7208043 13 #include "iomacros.h" // within MODDMA library.
AjK 12:1dfee7208043 14
AjK 12:1dfee7208043 15 // How long between grabbing GPIO FIO0PIN register.
AjK 15:e01144bae101 16 // Value is in microseconds. (500000 is half a second).
AjK 12:1dfee7208043 17 #define SAMPLE_PERIOD 500000
AjK 12:1dfee7208043 18
ktseng 18:e7d62a489a83 19 #define NUM_OF_SAMPLES 16
AjK 12:1dfee7208043 20
AjK 12:1dfee7208043 21 Serial pc(USBTX, USBRX);
AjK 12:1dfee7208043 22
AjK 12:1dfee7208043 23 DigitalOut led1(LED1);
AjK 12:1dfee7208043 24 DigitalOut led2(LED2);
AjK 12:1dfee7208043 25 DigitalOut led3(LED3);
AjK 12:1dfee7208043 26
AjK 12:1dfee7208043 27 uint32_t buffer[NUM_OF_SAMPLES];
AjK 12:1dfee7208043 28
AjK 12:1dfee7208043 29 bool dmaTransferComplete;
AjK 12:1dfee7208043 30
AjK 12:1dfee7208043 31 MODDMA dma;
AjK 16:cb10aec6feb1 32 MODDMA_Config *conf;
AjK 12:1dfee7208043 33
AjK 12:1dfee7208043 34 void TC0_callback(void);
AjK 12:1dfee7208043 35 void ERR0_callback(void);
AjK 12:1dfee7208043 36
AjK 12:1dfee7208043 37 int main() {
AjK 14:15939b260dfa 38 volatile int life_counter = 0;
AjK 14:15939b260dfa 39
ktseng 18:e7d62a489a83 40 // Sets bits 4-7 on port 0 to pulled down outputs.
ktseng 18:e7d62a489a83 41 p30_AS_OUTPUT; p30_MODE( PIN_PULLDOWN ); // P0.4
ktseng 18:e7d62a489a83 42 p29_AS_OUTPUT; p29_MODE( PIN_PULLDOWN ); // P0.5
ktseng 18:e7d62a489a83 43 p8_AS_OUTPUT; p8_MODE( PIN_PULLDOWN ); // P0.6
ktseng 18:e7d62a489a83 44 p7_AS_OUTPUT; p7_MODE( PIN_PULLDOWN ); // P0.7
AjK 12:1dfee7208043 45
AjK 12:1dfee7208043 46 // Clear the buffer.
AjK 12:1dfee7208043 47 memset(buffer, 0, sizeof(buffer));
AjK 12:1dfee7208043 48
AjK 12:1dfee7208043 49 // Set-up timer1 as a periodic timer.
AjK 12:1dfee7208043 50 LPC_SC->PCONP |= (1UL << 2); // TIM1 On
AjK 12:1dfee7208043 51 LPC_SC->PCLKSEL0 |= (3UL << 4); // CCLK/8 = 12MHz
AjK 12:1dfee7208043 52 LPC_TIM1->PR = 11; // TC clocks at 1MHz.
AjK 12:1dfee7208043 53 LPC_TIM1->MCR = 2; // Reset TCR to zero on match.
AjK 12:1dfee7208043 54 LPC_TIM1->MR0 = SAMPLE_PERIOD;
AjK 12:1dfee7208043 55
AjK 12:1dfee7208043 56 // Prepare the GPDMA system.
AjK 12:1dfee7208043 57 conf = new MODDMA_Config;
AjK 12:1dfee7208043 58 conf
AjK 12:1dfee7208043 59 ->channelNum ( MODDMA::Channel_0 )
ktseng 18:e7d62a489a83 60 ->srcMemAddr ( (uint32_t)&buffer[0] ) //Buffer data to be transferred
ktseng 18:e7d62a489a83 61 ->dstMemAddr ( (uint32_t)&LPC_GPIO0->FIOPIN ) //GPIO to be transferred
AjK 12:1dfee7208043 62 ->transferSize ( NUM_OF_SAMPLES )
ktseng 18:e7d62a489a83 63 ->transferType ( MODDMA::m2g ) // pseudo transfer code MODDMA understands.
AjK 12:1dfee7208043 64 ->transferWidth ( MODDMA::word )
AjK 12:1dfee7208043 65 ->srcConn ( MODDMA::MAT1_0 )
AjK 12:1dfee7208043 66 ->dmacSync ( MODDMA::MAT1_0 )
AjK 12:1dfee7208043 67 ->attach_tc ( TC0_callback )
AjK 12:1dfee7208043 68 ->attach_err ( ERR0_callback )
AjK 12:1dfee7208043 69 ; // end conf.
AjK 12:1dfee7208043 70
AjK 12:1dfee7208043 71 // Prepare configuration.
AjK 12:1dfee7208043 72 if (!dma.Setup( conf )) {
AjK 12:1dfee7208043 73 error("Doh!");
AjK 12:1dfee7208043 74 }
AjK 12:1dfee7208043 75
AjK 12:1dfee7208043 76 // Enable GPDMA to be ready for the TIM1 "ticks".
AjK 12:1dfee7208043 77 dma.Enable( conf );
AjK 12:1dfee7208043 78
AjK 12:1dfee7208043 79 // Begin.
AjK 12:1dfee7208043 80 LPC_TIM1->TCR = 1;
AjK 12:1dfee7208043 81
AjK 14:15939b260dfa 82 while (1) {
AjK 14:15939b260dfa 83 if (life_counter++ > 1000000) {
AjK 14:15939b260dfa 84 led1 = !led1; // Show some sort of life.
AjK 14:15939b260dfa 85 life_counter = 0;
AjK 14:15939b260dfa 86 }
AjK 12:1dfee7208043 87
AjK 12:1dfee7208043 88 if (dmaTransferComplete) {
AjK 12:1dfee7208043 89 dmaTransferComplete = false;
AjK 12:1dfee7208043 90 for (int i = 0; i < NUM_OF_SAMPLES; i++) {
AjK 12:1dfee7208043 91 int val = (buffer[i] >> 4) & 0xF;
AjK 12:1dfee7208043 92 pc.printf("Buffer index %d = 0x%x\n", i, val);
AjK 12:1dfee7208043 93 }
AjK 13:846c8b6ffb7f 94 pc.printf("Done.\n");
AjK 13:846c8b6ffb7f 95
AjK 13:846c8b6ffb7f 96 // Schedule another grab.
AjK 13:846c8b6ffb7f 97 if (dma.Setup( conf )) {
AjK 14:15939b260dfa 98 dma.Enable( conf );
AjK 13:846c8b6ffb7f 99 }
AjK 12:1dfee7208043 100 }
AjK 12:1dfee7208043 101 }
AjK 12:1dfee7208043 102 }
AjK 12:1dfee7208043 103
AjK 12:1dfee7208043 104 // Configuration callback on TC
AjK 12:1dfee7208043 105 void TC0_callback(void) {
AjK 12:1dfee7208043 106
AjK 12:1dfee7208043 107 // Just show sample sequence grab complete.
AjK 12:1dfee7208043 108 led3 = !led3;
AjK 14:15939b260dfa 109
AjK 12:1dfee7208043 110 // Get configuration pointer.
AjK 12:1dfee7208043 111 MODDMA_Config *config = dma.getConfig();
AjK 12:1dfee7208043 112
AjK 12:1dfee7208043 113 // Finish the DMA cycle by shutting down the channel.
AjK 12:1dfee7208043 114 dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
AjK 12:1dfee7208043 115
AjK 12:1dfee7208043 116 // Tell main() while(1) loop to print the results.
AjK 12:1dfee7208043 117 dmaTransferComplete = true;
AjK 12:1dfee7208043 118
AjK 12:1dfee7208043 119 // Clear DMA IRQ flags.
AjK 12:1dfee7208043 120 if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
AjK 13:846c8b6ffb7f 121 if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq();
AjK 12:1dfee7208043 122 }
AjK 12:1dfee7208043 123
AjK 12:1dfee7208043 124 // Configuration callback on Error
AjK 12:1dfee7208043 125 void ERR0_callback(void) {
AjK 12:1dfee7208043 126 error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem");
AjK 12:1dfee7208043 127 }