UART4 DMA Rx Problem

[leventeyigel52]

Posted on April 04, 2014 at 13:21

I cannot get into DMA mode, the code  I wrote did not get into DMA  interrupt. The code I wrote is as follows. Any advice?( my processor is STM32F103ZG)

 uint8_t RxBuffer1[100];  /*UART - Pin Config*/  GPIO_InitTypeDef GPIO_InitStructure;  USART_InitTypeDef USART_InitStructure;  NVIC_InitTypeDef NVIC_InitStructure;  DMA_InitTypeDef DMA_InitStructure;;   /* Clock configuration -------------------------------------------------------*/  RCC_APB2PeriphClockCmd( UART_GPIO_CLK_TX | UART_GPIO_CLK_RX | RCC_APB2Periph_AFIO, ENABLE);  RCC_APB1PeriphClockCmd(UART_CLK , ENABLE);  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2,ENABLE);  /* Configure the GPIO ports( UART4 Transmit and Receive Lines) */   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  GPIO_InitStructure.GPIO_Pin =  UART_TxPin;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(UART_GPIO_TX, &GPIO_InitStructure);   /* Configure the UART4_Rx as input floating */  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  GPIO_InitStructure.GPIO_Pin = UART_RxPin ;  GPIO_Init(UART_GPIO_RX, &GPIO_InitStructure);    USART_InitStructure.USART_BaudRate = 1200;  USART_InitStructure.USART_WordLength = USART_WordLength_9b;  USART_InitStructure.USART_StopBits = USART_StopBits_1;  USART_InitStructure.USART_Parity = USART_Parity_Even;  USART_InitStructure.USART_HardwareFlowControl =     USART_HardwareFlowControl_None;  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;      /* UART Guard Time set to 16 Bit */  USART_SetGuardTime(UART4, 8);   USART_Init(UART4, &USART_InitStructure);   /* Enable the UART4 */  USART_Cmd(UART4, ENABLE);      /************************* DMA *****************************/  DMA_DeInit(DMA2_Channel3);  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&UART4->DR;  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RxBuffer1;   DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; // Receive   DMA_InitStructure.DMA_BufferSize = 1;   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_Normal;   DMA_InitStructure.DMA_Priority = DMA_Priority_High;   DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;   DMA_Init(DMA2_Channel3, &DMA_InitStructure);   /* Enable the USART Rx DMA request */  USART_DMACmd(UART4, USART_DMAReq_Rx, ENABLE);   /* Enable DMA Transfer Complete interrupt */  DMA_ITConfig(DMA2_Channel3, DMA_IT_TC, ENABLE);    /* Enable the DMA RX Stream */  DMA_Cmd(DMA2_Channel3, ENABLE);  /* Enable the UART4 RX DMA Interrupt */  NVIC_InitStructure.NVIC_IRQChannel = DMA2_Channel3_IRQn;  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;  NVIC_Init(&NVIC_InitStructure);  /*******************************************************************/ void DMA2_Channel3_IRQHandler(){  if(DMA_GetITStatus(DMA2_IT_TC3)){        Uart_Interrupt_Handler();        DMA_ClearITPendingBit(DMA2_IT_TC3);  }

[waclawek.jan]

Posted on April 04, 2014 at 13:40

>

  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; // Receive

? JW

[leventeyigel52]

Posted on April 04, 2014 at 13:47

Don't we choose ''DMA_DIR_PeripheralDST'' when interrupt comes Rx Pin ?

[Tesla DeLorean]

Posted on April 04, 2014 at 13:52

Don't we choose ''DMA_DIR_PeripheralDST'' when interrupt comes Rx Pin ?

NO, you're configuring a DMA transaction, which you want to READ the Peripheral register, and WRITE to Memory, this would mean the Peripheral is the SOURCE (SRC), right?

[leventeyigel52]

Posted on April 04, 2014 at 14:00

Is my BufferSize correct ? 

I want to get into IRQ for each byte ? 

[leventeyigel52]

Posted on April 04, 2014 at 14:08

I changed the DMA_DIR_PeripheralDST to DMA_DIR_PeripheralSRC .

But i cannot still get into the interrupt 

[Tesla DeLorean]

Posted on April 04, 2014 at 14:37

If you use Normal mode you'll need to reinitialize the DMA on each interrupt

[leventeyigel52]

Posted on April 04, 2014 at 14:54

I changed the DMA_InitStructure.DMA_Mode to  DMA_Mode_Circular but the problem has not solved. 

Is there an error on IRQ Configuring ?

[leventeyigel52]

Posted on April 04, 2014 at 16:20

to be migrated, sourceId: 40316:697285D7-A9CA-445D-B16C-F23BF0E3B1A3

[Tesla DeLorean]

Posted on April 04, 2014 at 17:30

The last version is following below. I cannot understand where is the wrong ?

A cursory review suggests the code is not unreasonable, although I honestly can't see the point of doing a one byte DMA, and how that's materially more useful than just doing an RXNE interrupt. Are you actually receiving any data? If you make a simple polled mode version, or echo back, does that actually work?