STM32 SPI不能收发，状态总是reset，谁能指点一下。

只看该作者 · 2013-7-4 14:14

SPI初始化：

GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef  SPI_InitStructure;

/* Enable SPI1 and GPIOA clocks */
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA, ENABLE );//
RCC_APB1PeriphClockCmd( RCC_APB2Periph_SPI1,  ENABLE );//

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;  //SCK MOSI
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_IPU; //MISO
  GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_Out_PP; //NSS
  GPIO_Init(GPIOA, &GPIO_InitStructure);

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;  //
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;  //
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;  //
SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;  //
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; //
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;  //
//SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;  //
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;  //
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //
SPI_InitStructure.SPI_CRCPolynomial = 7; //
SPI_Init(SPI1, &SPI_InitStructure);  //

SPI_Cmd(SPI1, ENABLE); //

********************************************************************************

收发函数：

u8 SPI1_ReadWriteByte(u8 TxData)
{
u8 retry=0;
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET) // ----------------------在这里总是等于RESET
  {
  retry++;
  if(retry>200)
return 0;
  }
SPI_I2S_SendData(SPI1, TxData); //
retry=0;
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET) //
  {
  retry++;
  if(retry>200)
return 0;
  }
return SPI_I2S_ReceiveData(SPI1); //
}