SAML21走起19:DMA

#include <asf.h>

#define DATA_LENGTH (512)

static uint8_t source_memory[DATA_LENGTH];

static uint8_t destination_memory[DATA_LENGTH];

static volatile bool transfer_is_done = false;

COMPILER_ALIGNED(16)

DmacDescriptor example_descriptor;

static void transfer_done(struct dma_resource* const resource )

{

        transfer_is_done = true;

}

static void configure_dma_resource(struct dma_resource *resource)

{

        struct dma_resource_config config;

        dma_get_config_defaults(&config);

        dma_allocate(resource, &config);

}

static void setup_transfer_descriptor(DmacDescriptor *descriptor )

{

        struct dma_descriptor_config descriptor_config;

        dma_descriptor_get_config_defaults(&descriptor_config);

        descriptor_config.block_transfer_count = sizeof(source_memory);

        descriptor_config.source_address = (uint32_t)source_memory +

        sizeof(source_memory);

        descriptor_config.destination_address = (uint32_t)destination_memory +

        sizeof(source_memory);

        dma_descriptor_create(descriptor, &descriptor_config);

}









int main (void)

{

        system_init();

         struct dma_resource example_resource;

        configure_dma_resource(&example_resource);

        setup_transfer_descriptor(&example_descriptor);

        dma_add_descriptor(&example_resource, &example_descriptor);

        dma_register_callback(&example_resource, transfer_done,

        DMA_CALLBACK_TRANSFER_DONE);

        dma_enable_callback(&example_resource, DMA_CALLBACK_TRANSFER_DONE);

        for (uint32_t i = 0; i < DATA_LENGTH; i++) {

                source_memory[i] = i;

        }

        

          dma_start_transfer_job(&example_resource);

          dma_trigger_transfer(&example_resource);

          while (!transfer_is_done) {

                  /* Wait for transfer done */

          }

          while (true) {

                  /* Nothing to do */

          }

}