No interrupt from DMA

[heinz]

Posted on September 29, 2016 at 15:13

I'm trying to receive serial data using USART1 and DMA in 3 different chunks.

Between I'm setting the buffer size in the DMA (2 bytes, 1 byte, 10 bytes) using the function set_ dma _buffer_size() . The first two attempts are OK. I get an interrupt from DMA after 2 bytes and 1 byte. However when the last 10 bytes arrives, I don't get any interrupt at all. The last 10 bytes are in concecutive order. So can anyone see what I'm doing wrong here?

void
GPIO_Usart_1_Configuaration(
void
)
{
GPIO_InitTypeDef GPIO_InitStructure;
// enable USART clocks
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
// setup port A
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | 
// USART1_TX
GPIO_Pin_10; 
// USART1_RX
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_7);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_7);
GPIO_Init(GPIOA, &GPIO_InitStructure);
// setup USART1
USART_InitTypeDef USART_InitStructure;
USART_ClockInitTypeDef USART_ClockInitStructure;
// setup USART1_ClockInitStruct member with its default value
USART_ClockStructInit(&USART_ClockInitStructure);
USART_ClockInit(USART1, &USART_ClockInitStructure);
USART_InitStructure.USART_BaudRate = BAUDRATE_57600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
// enable DMA interface for RX
USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE); 
// USART_CR3, mdw 0x40013808
// enable USART1 port
USART_Cmd(USART1, ENABLE);
}
void
GPIO_Dma_1_Configuaration(
void
)
{
DMA_InitTypeDef DMA_InitStructure;
// enable DMA clocks
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
/* DMA2 channel5 configuration */
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->RDR; 
// DMA_CPAR, mdw 0x40020060
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)rx_buffer; 
// DMA_CMAR, mdw 0x40020064
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 10; 
// DMA_CNDTR, mdw 0x4002005C
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High; 
// DMA_CCR, mdw 0x40020058
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5, &DMA_InitStructure);
// enable DMA interrupt
NVIC_EnableIRQ(DMA1_Channel5_IRQn);
// enable transfer complete interrupt
DMA_ITConfig(DMA1_Channel5, DMA_IT_TC, ENABLE); 
// DMA_CCR, mdw 0x4002 0058
// enable DMA1 channel5
DMA_Cmd(DMA1_Channel5, ENABLE);
}

void
DMA1_Channel5_IRQHandler(
void
)
{
// handle DMA IRQ
}
void
set_dma_buffer_size(
int
bufferSize)
{
DMA1_Channel5->CCR &= ~DMA_CCR_EN; 
// DMA_CCR, mdw 0x40020058
DMA1_Channel5->CCR &= ~DMA_CCR_TCIE;
DMA1_Channel5->CNDTR = (uint32_t)bufferSize; 
// DMA_CNDTR, mdw 0x4002005C
DMA1_Channel5->CCR |= DMA_CCR_TCIE;
DMA1_Channel5->CCR |= DMA_CCR_EN;
}

int
main()
{
GPIO_Usart_1_Configuaration();
GPIO_Dma_1_Configuaration();
set_dma_buffer_size(2);
set_dma_buffer_size(RX_BUFFER_SIZE_2);
// handle DMA IRQ first time, OK
set_dma_buffer_size(1);
set_dma_buffer_size(RX_BUFFER_SIZE_1);
// handle DMA IRQ second time, OK
set_dma_buffer_size(10);
set_dma_buffer_size(RX_BUFFER_SIZE_10);
// handle DMA IRQ third time, not OK
}

[heinz]

Posted on September 29, 2016 at 16:32

Just to clarify.

I actually noticed that in the interrupt handler the if statement is'nt fulfilled the second time.

void DMA1_Channel5_IRQHandler(void)
{
if (DMA_GetITStatus(DMA1_IT_TC5))
{
DMA_ClearITPendingBit(DMA1_IT_GL5);
}
}

[heinz]

Posted on September 29, 2016 at 17:04

Ooops! I thougt there was a problem with my configuration of USART/DMA. It turned out the problem was my own fault later in the code.

So my problem is fixed. Sorry for the interrupt.