stm32f10x DMA RX Interupt ....

[redkofka]

Posted on June 18, 2012 at 07:40

HI I want to use DMA to Recieving data via uart (rs485)

 I want to use 20byte buffer but for siplicity in this exaple is shown only 1byte buffer...  int main(void){  RCC_Configuration();  GPIO_Configuration();  USART_Configuration();  DMA_Configuration();  NVIC_Configuration_DMA_RX();  while(1){  };  }  /******************************************************************************/  void RCC_Configuration(void)  {  /* Enable DMA clock */  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);  /* Enable GPIO bank clock */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);  /* Enable UART clock */  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);  }  /******************************************************************************/  void GPIO_Configuration(void)  {  GPIO_InitTypeDef GPIO_InitStructure;  /* Configure USART Tx as alternate function push-pull */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; // PA.09 USART1.TX  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_Init(GPIOA, &GPIO_InitStructure);  /* Configure USART Rx as input floating */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; // PA.10 USART1.RX  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  GPIO_Init(GPIOA, &GPIO_InitStructure);  }  /******************************************************************************/  void USART_Configuration(void)  {  USART_InitTypeDef USART_InitStructure;  /* USART resources configuration (Clock, GPIO pins and USART registers) ----*/  /* USART configured as follow:  - BaudRate = 115200 baud  - Word Length = 8 Bits  - One Stop Bit  - No parity  - Hardware flow control disabled (RTS and CTS signals)  - Receive and transmit enabled  */  USART_InitStructure.USART_BaudRate = 115200;  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_RTS;  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;  /* USART configuration */  USART_Init(USART1, &USART_InitStructure);  /* Enable the USART1 */  USART_Cmd(USART1, ENABLE);  USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);  /* Enable DMA Requests*/  USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);  USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);  }  /******************************************************************************/  /**  * @Brief  * @Parameter None  *  * @Return None  */  void DMA_Configuration(void)  {  // USART1 Channel 4, USART2 Channel 7, USART3 Channel 2  /***TX********************/  DMA_DeInit(DMA1_Channel4);  DMA_Cmd(DMA1_Channel4, DISABLE);  /***RX********************/  DMA_DeInit(DMA1_Channel5);  DMA_Cmd(DMA1_Channel5, DISABLE);  }  /******************************************************************************/  void DMA_USART_Rx (void){  DMA_InitTypeDef DMA_InitStructure;  DMA_DeInit(DMA1_Channel5);  DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART1->DR;  DMA_InitStructure.DMA_MemoryBaseAddr = (u32)RXpacket;  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;  DMA_InitStructure.DMA_BufferSize = 1; //20 in the end  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_ITConfig(DMA1_Channel5,DMA_IT_TC,ENABLE);  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;  DMA_ClearFlag(DMA1_FLAG_TC5);  DMA_Init(DMA1_Channel5, &DMA_InitStructure);  DMA_Cmd(DMA1_Channel5, ENABLE);  /* Wait of DMA completion */  USART_Cmd(USART2, ENABLE);  DMA_ITConfig(DMA1_Channel5, DMA_IT_TC , ENABLE);  while(DMA_GetFlagStatus(DMA1_FLAG_TC5) == RESET);  /* Loop until the end of transmit */  while(USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);  }  /******************************************************************************/  void NVIC_Configuration_DMA_RX(void)  {  NVIC_InitTypeDef NVIC_InitStructure;  //Enable the USARRx Interrupt  NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel5_IRQn ;  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//ENABLE  NVIC_Init(&NVIC_InitStructure);  /******************************************************************************/  void DMA1_Channel5_IRQHandler(void)  {  /*This part never start*/  }  /******************************************************************************/  BUT WHEN I USED :  /******************************************************************************/  void NVIC_Configuration_Irq(void)  {  NVIC_InitTypeDef NVIC_InitStructure;  //Enable the USART_Rx Interrupt  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//ENABLE  NVIC_Init(&NVIC_InitStructure);  }  /******************************************************************************/  void USART1_IRQHandler(void) //Reading data  {  GPIO_WriteBit(LED_PORT, GPIO_Pin_13, Bit_SET);  if ((USART1->SR & USART_FLAG_RXNE) != (u16)RESET);  DMA_USART_Rx();  }  /******************************************************************************/   iTS FIRST TIME GO IN USART1 INTERUPT AND THEN IN DMA1_Channel5....   sorry about your time but i cant find some DMA Rx example .....  second problem is that i want to use 20byte buffer - but in debugger always i recieve only firt  i use -DMA_InitStructure.DMA_BufferSize = 20; and in debugger i see that first is recieved bud only firt  isnt problem that dma cant read whole buffer -its read one by one ?  somewhere i read that the DMA_IT_TC is possible to use only in M2M mode ....  would you be so kind and take a look at code  thanks

[alok472]

Posted on June 18, 2012 at 15:38

Suggest to download STM32F2xx Standard Peripheral Library example ?For USART, there is an example of 2 boards communication.

(\USART\USART_TwoBoards\DataExchangeDMA) The readme.txt says ''In both boards, the data transfers is managed using the USART Tx/Rx channels DMA requests.'' hope it helps

[redkofka]

Posted on June 26, 2012 at 08:50

thanks i ll check it.