When the basic timer performs interrupt processing, transmission of communication by DMA delays the
If I generate a 2kHz interrupt process using a basic timer and perform several SPI communications with DMA during that cycle, the generation of the 2kHz interrupt process is delayed by roughly the interrupt time in DMA.
Can you please provide a solution to avoid the delay?
The following excerpted source is included for reference.
■stm32f7xx_it.c
/* 2 kHz cycle task */
void TIM7_IRQHandler(void)
{
/* USER CODE BEGIN TIM7_IRQn 0 */
/* USER CODE END TIM7_IRQn 0 */
HAL_TIM_IRQHandler(&htim7);
/* USER CODE BEGIN TIM7_IRQn 1 */
/* USER CODE BEGIN Callback 1 */
StartCommunication();
/* USER CODE END TIM7_IRQn 1 */
}
void DMA2_Stream4_IRQHandler(void)
{
/* USER CODE BEGIN DMA2_Stream4_IRQn 0 */
/* USER CODE END DMA2_Stream4_IRQn 0 */
HAL_DMA_IRQHandler(&hdma_spi5_tx);
/* USER CODE BEGIN DMA2_Stream4_IRQn 1 */
if(hdma_spi5_tx.State == HAL_DMA_STATE_BUSY || hdma_spi5_rx.State == HAL_DMA_STATE_BUSY){
return;
}
StartCommunication();
/* USER CODE END DMA2_Stream4_IRQn 1 */
}
■main.c
void StartCommunication()
{
static int cnt = 0;
if(cnt >= 5){
cnt = 0;
return;
}
cnt++;
char cmd[4] = {0xff, 0xff, 0xff, 0xff};
char buf[4] = {0xff, 0xff, 0xff, 0xff};
HAL_StatusTypeDef status = HAL_OK;
status = HAL_SPI_TransmitReceive_DMA(&hspi5, cmd, buf, 4);
}