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我使用的是STM32F4發現板，我試圖用DMA獲得SPI回送。 我已經成功地得到一個「SPI-只」環回跑，但現在我想除了與SPI使用DMA，這裏的功能正在使用：帶DMA的SPI回送
SPI的初始化[編輯]
void init_SPI1(void){
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStruct;
SPI_InitTypeDef SPI_InitStruct ;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_6 | GPIO_Pin_5|GPIO_Pin_4;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStruct);
// connect SPI1 pins to SPI alternate function
GPIO_PinAFConfig(GPIOA, GPIO_PinSource4, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);
//Set chip select high
GPIOA->BSRRL |= GPIO_Pin_4; // set PA4 high
// enable SPI1 peripheral clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
/* configure SPI1 in Mode 0
* CPOL = 0 --> clock is low when idle
* CPHA = 0 --> data is sampled at the first edge*/
SPI_StructInit(&SPI_InitStruct); // set default settings
SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex; // set to full duplex mode, seperate MOSI and MISO lines
SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // transmit in master mode, NSS pin has to be always high
SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b; // one packet of data is 8 bits wide
SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low; // clock is low when idle
SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge; // data sampled at first edge
SPI_InitStruct.SPI_NSS = SPI_NSS_Soft ; // set the NSS management to internal and pull internal NSS high
SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4; // SPI frequency is APB2 frequency/4
SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;// data is transmitted MSB first
SPI_Init(SPI1, &SPI_InitStruct);
NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
SPI_I2S_ITConfig(SPI1,SPI_I2S_IT_RXNE,ENABLE);
return;
}
DMA的配置[編輯]：
void DMA_Config()
{
DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
DMA_ClearFlag(DMA2_Stream5, DMA_FLAG_FEIF2|DMA_FLAG_DMEIF2|DMA_FLAG_TEIF2|DMA_FLAG_HTIF2|DMA_FLAG_TCIF2);
DMA_Cmd(DMA2_Stream5, DISABLE);
while (DMA2_Stream5->CR & DMA_SxCR_EN);
DMA_DeInit(DMA2_Stream5);
DMA_StructInit(&DMA_InitStructure);
DMA_InitStructure.DMA_Channel = DMA_Channel_3;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) &(SPI1->DR);
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t) &spiTxBuff;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = SPI_TX_MAX;
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_FIFOMode = DMA_FIFOMode_Disable;
DMA_Init(DMA2_Stream5, &DMA_InitStructure);
/**
configuration of the interrupts of DMA
******************************************************/
DMA_ITConfig(DMA2_Stream5, DMA_IT_TC, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
return;
}
SPI寫功能：
void SPI1_Write(uint8_t *txBuff,int length,tSPI_Callback fct)
{
DMA2_Stream5->M0AR = (uint32_t) &spiTxBuff;
DMA_Cmd(DMA2_Stream5, ENABLE);
SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Tx, ENABLE);
SPI_Cmd(SPI1, ENABLE);
}
使用spi中斷處理程序將接收到的數據寫入Rx緩衝區。
void SPI1_IRQHandler()
{
spiRxBuff[spiRxCount] = SPI_I2S_ReceiveData(SPI1);
spiRxCount++;
}
我打電話主這些功能如下：
的main.c：
DMA_Config();
init_SPI1();
SPI1_Write(spiTxBuff,SPI_TX_MAX,(void*)0);
使用調試器，我發現，在高DMA中斷狀態寄存器，TCIF5（轉讓完成標誌）和HTIF5（半傳輸完成標誌）設置爲1意味着傳輸成功完成，但我沒有在SPI Rx緩衝區中獲得任何數據，第二個奇怪的是DMA中斷和SPI中斷被觸發。你能幫我弄清楚我的代碼有什麼問題。
編輯
的DMA和SPI中斷觸發，但問題是現在我得到的是我不能接受的所有元素，我可以收到第一個
uint8_t spiTxBuff[SPI_TX_MAX] = {0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x10};
但spiRxBuff[SPI_RX_MAX] ={0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00}
這個問題是由於DMA比中斷處理程序更快，所以SPI中斷處理程序沒有時間來處理所有接收到的數據？
在代碼中有一個對DMA1的引用。應該是「DMA2」嗎？ – kkrambo
是的，你是對的謝謝 – fedi