Hi,
i need an exampe for RX over DMA.
The one from stm is with fixed buffersize.
But i want to do the input with dynamic lenght.
I dont know how to implement this. The following Code works only with fixed size. Therefore every 4 input i make on terminal is stored in RxBuffer.
#define countof(a) (sizeof(a) / sizeof(*(a)))
uint8_t RxBuffer[5];
#define RxBufferSize (countof(RxBuffer) - 1)
void DMA1_Channel6_handler() __attribute__((interrupt));
static void DMA_Config_Usart2RX(void)
{
DMA1_Channel6->CCR = (DMA_Priority_Low |
DMA_PeripheralDataSize_Byte |
DMA_MemoryDataSize_Byte |
DMA_PeripheralInc_Disable |
DMA_MemoryInc_Enable |
DMA_Mode_Normal |
DMA_DIR_PeripheralSRC |
DMA_CCR4_TCIE
);
DMA1_Channel6->CPAR = (u32)&USART2->DR;
DMA1_Channel6->CMAR = (u32)RxBuffer;
DMA1_Channel6->CNDTR = RxBufferSize;
NVIC_ENABLE_INT(DMA1_Channel6_IRQChannel);
NVIC_SET_PRIORITY(DMA1_Channel6_IRQChannel, 2);
DMA1_Channel6->CCR |=DMA_CCR6_EN;
}
void DMA1_Channel6_handler()
{
DMA1->IFCR = DMA_IFCR_CGIF6;
DMA_Config_Usart2RX();
}
