Do some homework assigned by the lecture but have no direction so ask for some help.
I need to write a function DMASpeed() to demosntrate the speed improvement of DMA over a software loop for memory to memory transfers. I include polling DMA for my homework. I need to transfer as larger a block of data as possible, allocating memory using malloc() for the source and destination. Also to measure the timing, toggle a GPIO pin look at the timing on the oscilloscope or logic analyser.
static char src[]="*Hello*";
static volatile char dst[8]={0,0,0,0,0,0,0,0}; // Ensure NULL terminated
void
DMASpeed (void)
{
// Initial value
printf("BEFORE: dst = '%s'\n", dst);
// Transfer
printf("Initiate DMA Transfer...\n");
HAL_DMA_Start (&hdma_memtomem_dma2_stream0, (uint32_t) src, (uint32_t) dst, 2);
printf("DMA Transfer initiated.\n");
// Poll for DMA completion
printf("Poll for DMA completion.\n");
HAL_DMA_PollForTransfer(&hdma_memtomem_dma2_stream0, HAL_DMA_FULL_TRANSFER, HAL_MAX_DELAY);
printf("DMA complete.\n");
// Print result
printf("AFTER: dst = '%s'\n", dst);
}
Can anyone give a brief about the work and how i going to implement it.
