本例程需要用杜邦线将MISO和MOSI两个GPIO短路，即可完成自发自收的测试程序。
1 SPI初始化
void SPIM_Init(SPI_TypeDef* SPIx, unsigned short spi_baud_div)
{
SPI_InitTypeDef SPI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA | RCC_AHBPeriph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_3); //SPI_NSS PA0
#ifdef DISSWDIO
GPIO_PinAFConfig(GPIOA, GPIO_PinSource13, GPIO_AF_4); //SPI_MISO
#else
GPIO_PinAFConfig(GPIOA, GPIO_PinSource12, GPIO_AF_4); //SPI_MISO
#endif
GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_4); //SPI_MOSI
GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_3); //SPI_SCK
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //SPI_NSS PA0
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //Push to avoid multiplexing output
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14; //SPI_MOSI | SPI_SCK
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
#ifdef DISSWDIO
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13; //SPI_MISO
#else
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12; //SPI_MISO
#endif
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //Pull-up input
GPIO_Init(GPIOA, &GPIO_InitStructure);
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_DataWidth = SPI_DataWidth_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = spi_baud_div;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_Init(SPIx, &SPI_InitStructure);
SPI_Cmd(SPIx, ENABLE);
SPIM_TXEn(SPIx);
SPIM_RXEn(SPIx);
}
void SPI_DMA_RX_Init()
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //ʹÄÜDMA´«Êä
DMA_DeInit(DMA1_Channel4);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) & (SPI2->RXREG); //SPI½ÓÊÕÊý¾Ý¼Ä´æÆ÷
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)rxdata; //SPI½ÓÊÕµ½µÄÊý¾Ý´æ·Å»ùµØÖ·
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;//Êý¾Ý´ÓÍâÉèµ½memory
DMA_InitStructure.DMA_BufferSize = 20;
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_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel4, &DMA_InitStructure);//SPI2 RXΪDMAͨµÀ4
}
void SPI_DMA_TX_Init()
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //ʹÄÜDMA´«Êä
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) & (SPI2->TXREG); //SPI·¢ËÍÊý¾Ý¼Ä´æÆ÷
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)txdata;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;//Êý¾Ý´Ómemoryµ½ÍâÉè
DMA_InitStructure.DMA_BufferSize = 8;//·¢ËÍÊý¾Ý¸öÊý
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//ÍâÉèµØÖ·²»¸Ä±ä
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//memoryµØÖ·µÝÔö¿ªÆô
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;//ÆÕͨģʽ
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5, &DMA_InitStructure);//SPI RXΪDMAͨµÀ5
}
2 SPI读写接口函数
void SPI2MasterReadWritebuf(u8 *ptx_buf, u8 *prx_buf, u32 len)
{
DRV_DMA_TransmitPacket(DMA1_Channel5, (u32)ptx_buf, len);
DRV_DMA_TransmitPacket(DMA1_Channel4, (u32)prx_buf, len);
SPIM_CSLow(SPI2);
SPI_DMACmd(SPI2, SPI_DMAReq_EN, ENABLE);
while(!DMA_GetFlagStatus(DMA1_FLAG_TC5));
DMA_ClearFlag(DMA1_FLAG_TC5);
while(!DMA_GetFlagStatus(DMA1_FLAG_TC4));
DMA_ClearFlag(DMA1_FLAG_TC4);
SPI_DMACmd(SPI2, SPI_DMAReq_EN, DISABLE);
SPIM_CSHigh(SPI2);
}
3 自发自收的测试函数
void SPI_master_DMA_TXRXloop_Test(void)
{
unsigned int i, j;
SPIM_Init(SPI2, 4); //SPI CLK = 48/2/4 =6MHz
SPI_DMA_RX_Init();
SPI_DMA_TX_Init();
UartSendGroup((u8*)printBuf, sprintf(printBuf, "SPI2 test\r\n"));
//while(1)
{
for(i = 1; i <= LENGTH; i++) {
for(j = 0; j < LENGTH; j++) {
rxdata[j] = 0x0;
}
//memset(rxdata,0,sizeof(rxdata));
SPI2MasterReadWritebuf(txdata, rxdata, i);
}
}
for(i = 0; i < LENGTH; i++) {
UartSendGroup((u8*)printBuf, sprintf(printBuf, "rx[%d]=0x%x\r\n", i, rxdata[i]));
}
j = 0;
for(i = 0; i < LENGTH; i++) {
if(rxdata[i] != txdata[i]) {
j = 1;
break;
}
}
if(j == 1) {
UartSendGroup((u8*)printBuf, sprintf(printBuf, "SPI2 TxRx Loopback test fail\r\n"));
} else {
UartSendGroup((u8*)printBuf, sprintf(printBuf, "SPI2 TxRx Loopback test Sucessful\r\n"));
}
UartSendGroup((u8*)printBuf, sprintf(printBuf, "SPI2 test over\r\n"));
}
4 串口打印信息
sprintf ok
Start SPI test
SPI2 test
rx[0]=0x55
rx[1]=0xaa
rx[2]=0xbb
rx[3]=0xdd
rx[4]=0x33
rx[5]=0x77
rx[6]=0x22
rx[7]=0x11
rx[8]=0x55
rx[9]=0xaa
rx[10]=0xbb
rx[11]=0xdd
rx[12]=0x33
rx[13]=0x77
rx[14]=0x22
rx[15]=0x11
SPI2 TxRx Loopback test Sucessful
SPI2 test over
