spi通信中，mosi能发出去数据，但是miso返回不了数据

小麻8 · 发表于 2015-12-7 21:10:03

我用逻辑分析仪看的是SCK有波形，mosi也有波形，只有miso没有波形

void SPI2_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;

RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );//PORTB?±??????
RCC_APB1PeriphClockCmd( RCC_APB1Periph_SPI2, ENABLE );//SPI2?±??????

// GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //PB13/14/15???????ì????
// GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
// GPIO_Init(GPIOB, &GPIO_InitStructure);//??????GPIOB
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //????
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_15;//sck mosi
GPIO_Init(GPIOB,&GPIO_InitStructure);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //????
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;//sck mosi
GPIO_Init(GPIOB,&GPIO_InitStructure);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
//GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;//miso
GPIO_Init(GPIOB,&GPIO_InitStructure);

GPIO_SetBits(GPIOB,GPIO_Pin_6 | GPIO_Pin_13 | GPIO_Pin_15); //PB13/14/15????

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; //?è??SPI???ò?ò?????ò??????????:SPI?è???????????ò?????¤

//SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; //?¨???¨?????¤·???????:?¨?????¤·???????256

SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; //?è??SPI???????ó??:SPI·???????8?????á??
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; //?®???????±????????×???????????
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge; //?®???????±????????????±????¨?????ò?????©????±????ù
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSS???????????¨NSS?????©?????í???¨????SSI???©???í:????NSS??????SSI??????
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256; //?¨???¨?????¤·???????:?¨?????¤·???????256

SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //???¨??????????MSB??????LSB??????:??????????MSB??????,???????°
SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC?????????à????
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_Init(SPI2, &SPI_InitStructure); //?ù??SPI_InitStruct?????¨???????????????èSPIx?????÷

SPI_Cmd(SPI2, ENABLE); //????SPI???è

SPI2_ReadWriteByte(0xff);//????????

}

u8 SPI2_ReadWriteByte(u8 TxData)
{

u8 retry=0;
while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET) //?ì?é???¨??SPI±ê?????è????·?:·?????????±ê????
{
retry++;
if(retry>200)return 0;
}
SPI_I2S_SendData(SPI2, TxData); //?¨?????èSPIx·???????????
retry=0;

while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET) //?ì?é???¨??SPI±ê?????è????·?:????????·???±ê????
{
retry++;
if(retry>200)return 0;
}
return SPI_I2S_ReceiveData(SPI2); //·????¨??SPIx×??ü??????????

但是程序一直死在下面的循环里