Fork of Andy Kirkham's MODDMA GPDMA Controller for Mbed OS 6
Read MODDMA for more info.
example3.h
- Committer:
- hudakz
- Date:
- 21 months ago
- Revision:
- 20:01d0a680e45a
- Parent:
- 19:bf3ae4c3635d
File content as of revision 20:01d0a680e45a:
/* * Demonstrates capturing the GPIO P0.4 to P0.7 "nibble" to memory * using GPDMA. The transfers from port pins to memory buffer are * triggered using Timer1 MAT1.0 match compare. * * In this example all inputs have pullups. So with nothing connected * the P0.4/7 reads as 0xF. Connecting a wire from one or more of the four * inputs to ground will show up in the captured buffer sequence. */ #include "mbed.h" #include "MODDMA.h" #include "iomacros.h" // within MODDMA library. // How long between grabbing GPIO FIO0PIN register. // Value is in microseconds. (500000 is half a second). #define SAMPLE_PERIOD 500000 #define NUM_OF_SAMPLES 5 DigitalOut led1(LED1); DigitalOut led2(LED2); DigitalOut led3(LED3); uint32_t buffer[NUM_OF_SAMPLES]; bool dmaTransferComplete; MODDMA dma; MODDMA_Config* conf; void TC0_callback(void); void ERR0_callback(void); /** * @brief * @note * @param * @retval */ int main() { volatile int life_counter = 0; // Macros defined in iomacros.h, saves messing with DigitalIn p30_AS_INPUT; p30_MODE(PIN_PULLUP); // P0.4 p29_AS_INPUT; p29_MODE(PIN_PULLUP); // P0.5 p8_AS_INPUT; p8_MODE(PIN_PULLUP); // P0.6 p7_AS_INPUT; p7_MODE(PIN_PULLUP); // P0.7 // Clear the buffer. memset(buffer, 0, sizeof(buffer)); printf("Starting up...\n"); // Set-up timer1 as a periodic timer. LPC_SC->PCONP |= (1UL << 2); // TIM1 On LPC_SC->PCLKSEL0 |= (3UL << 4); // CCLK/8 = 12MHz LPC_TIM1->PR = 11; // TC clocks at 1MHz. LPC_TIM1->MCR = 2; // Reset TCR to zero on match. LPC_TIM1->MR0 = SAMPLE_PERIOD; // Prepare the GPDMA system. conf = new MODDMA_Config; conf->channelNum(MODDMA::Channel_0); conf->srcMemAddr((uint32_t) & LPC_GPIO0->FIOPIN); conf->dstMemAddr((uint32_t) & buffer[0]); conf->transferSize(NUM_OF_SAMPLES); conf->transferType(MODDMA::g2m); // pseudo transfer code MODDMA understands. conf->transferWidth(MODDMA::word); conf->srcConn(MODDMA::MAT1_0); conf->dmacSync(MODDMA::MAT1_0); conf->attach_tc(TC0_callback); conf->attach_err(ERR0_callback); // Prepare configuration. if (!dma.Setup(conf)) { error("Doh!"); } // Enable GPDMA to be ready for the TIM1 "ticks". dma.Enable(conf); // Begin. LPC_TIM1->TCR = 1; while (1) { if (life_counter++ > 1000000) { led1 = !led1; // Show some sort of life. life_counter = 0; } if (dmaTransferComplete) { dmaTransferComplete = false; for (int i = 0; i < NUM_OF_SAMPLES; i++) { int val = (buffer[i] >> 4) & 0xF; printf("Buffer index %d = 0x%x\n", i, val); } printf("Done.\n"); // Schedule another grab. if (dma.Setup(conf)) { dma.Enable(conf); } } } } // Configuration callback on TC void TC0_callback(void) { // Just show sample sequence grab complete. led3 = !led3; // Get configuration pointer. MODDMA_Config* config = dma.getConfig(); // Finish the DMA cycle by shutting down the channel. dma.Disable((MODDMA::CHANNELS) config->channelNum()); // Tell main() while(1) loop to print the results. dmaTransferComplete = true; // Clear DMA IRQ flags. if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq(); if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq(); } // Configuration callback on Error void ERR0_callback(void) { error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem"); }