我正在尝试使用DMA将数据发送到SPI1。然后,SPI1将控制DAC进行电压更新。
使用的芯片是STM32F407。因此,对应的通道/流是:channel 3/stream 5,如参考手册所示。然而,当DMA启用时,SPI1 1->DR没有显示数据,示波器也没有显示结果。
当SPI 1->DR由软件编写时,SPI工作正常。有人能帮我查一下发生了什么吗?下面是代码:
uint16_t DACData[1];
void InitDMA(void)
{
DMA_InitTypeDef DMA_InitStructure;
DMA_Cmd(DMA2_Stream2, DISABLE);
while (DMA2_Stream2->CR & DMA_SxCR_EN);
//SPI1 Tx DMA
DMA_DeInit(DMA2_Stream5);
DMA_StructInit(&DMA_InitStructure);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE); //Init DMA clock
DMA_InitStructure.DMA_Channel = DMA_Channel_3;//SPI1 Tx
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(SPI1->DR); //Set the SPI1 Tx
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&DACData; //Set the memory location
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral; //
DMA_InitStructure.DMA_BufferSize = 1; //Define the number of bytes to send
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //Normal mode (not circular)
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; //Operate in 'direct mode'
DMA_InitStructure.DMA_MemoryBurst =DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst =DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream5, &DMA_InitStructure); //DMA2, Channel 3, stream 5
//Enable the transfer complete interrupt for DMA2 Stream5
DMA_ITConfig(DMA2_Stream5, DMA_IT_TC, ENABLE);
}
下面是SPI1初始化的方式
void InitSPI1(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
SPI_InitTypeDef SPI_InitStruct;
// enable clock for used IO pins
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_6 | GPIO_Pin_5;
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_PinSource5, GPIO_AF_SPI1); //SCK
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1); //MISO
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1); //MOSI
// enable 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_InitStruct.SPI_Direction = SPI_Direction_1Line_Tx; // one line transmission
SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // transmit in master mode, NSS pin has to be always high
SPI_InitStruct.SPI_DataSize = SPI_DataSize_16b; // one packet of data is 16 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 | SPI_NSSInternalSoft_Set;; // set the NSS management to hardware
SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; // SPI frequency is APB2 frequency / 4 = 21MHz
SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;// data is transmitted MSB first
SPI_Init(SPI1, &SPI_InitStruct);
SPI_Cmd(SPI1, ENABLE); // enable SPI1
}
我尝试使用这些命令启动DMA:
DACData[0]=0xff00;
DMA_Cmd(DMA2_Stream5, ENABLE);
如果可能有帮助,下面是DMA2的注册值,Stream5
发布于 2014-06-02 08:44:37
我们已经错过了这样一条线:
SPI_I2S_DMACmd(SPI1,SPI_I2S_DMAReq_Tx,ENABLE);
它使SPI1能够使用DMA。
发布于 2015-01-19 16:49:41
只想补充一句:
如果您想重新启动DMA,那么似乎您必须调用的不仅仅是:
DMA_Cmd(DMA2_Stream5, ENABLE);
但
DMA_ClearFlag(DMA1_Stream5, DMA_FLAG_TCIF5);
也是。尽管我没有启用中断,但这似乎仍然是必需的。
发布于 2014-06-02 06:10:06
基于快速查看,最突出的是在启用DMA外设之前尝试使用部分DMA外围设备。尝试移动
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
打电话之前
DMA_Cmd(DMA2_Stream2, DISABLE);
while (DMA2_Stream2->CR & DMA_SxCR_EN);
这是可能的。被困在圈子里。(如果外围设备在读取寄存器时没有启用,我不确定这些位是如何读取的)
如果这没有帮助,留下评论,我可以试着看得更仔细一点。
https://stackoverflow.com/questions/23987461
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