Posted on May 27, 2013 at 13:17Hi, i'm using smt32F303 discovery board, I send / receive data on USART1 without problem if I use interrupt mode, so I think that hardware is good.
I want send a data buffer lenght ~ 8000 bytes using dma mode. Before I config GPIO , USART, and DMA , but on my hyperterminal receive only 4 chars , which is the problem?
this is my code:
unsigned char tx_buffer[8208];
void InitUSART1(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
USART_InitTypeDef USART_InitStructure;
// TX out mode
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOC, &GPIO_InitStructure);
// RX in mode
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_Init(GPIOC, &GPIO_InitStructure);
/* Connect PXx to USARTx_Tx */
GPIO_PinAFConfig(GPIOC,GPIO_PinSource4,GPIO_AF_7);
GPIO_PinAFConfig(GPIOC,GPIO_PinSource5,GPIO_AF_7);
/* Interrupt config */
EXTI_InitStructure.EXTI_Line = EXTI_Line25; //usart1
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
/* Enable and set EXTI0 Interrupt to the lowest priority */
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x07;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x07;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
USART_InitStructure.USART_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_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
/* USART configuration */
USART_Init(USART1, &USART_InitStructure);
/* interrupt */
USART_ITConfig(USART1,USART_IT_RXNE, ENABLE);
/* Enable USART */
USART_Cmd( USART1, ENABLE);
/* Enable DMA tx USART */
USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);
}
void SendBufferTx(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_DeInit(DMA1_Channel4);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->TDR;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&tx_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = sizeof(tx_buffer);
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Enable;
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_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel4, &DMA_InitStructure);
DMA_Cmd(DMA1_Channel4, ENABLE);
}
