STM32 SPI2无论是读还是写SPI_DR都是0000，求帮助

yuanzuo · 发表于 2013-7-10 17:59:23

.h文件部分代码
#define AFE4490_FLAG_TIMEOUT    ((uint32_t)0x1000)    //用于延时

   /* AFE4490 SPI Interface pins */          //AFE4490连接SPI2，对应PB12~PB15
#define AFE4490_SPI          SPI2
#define AFE4490_SPI_CLK    RCC_APB1Periph_SPI2

#define AFE4490_SPI_SCLK_PIN       GPIO_Pin_13    //PB13
#define AFE4490_SPI_SCLK_GPIO_PORT GPIOB
#define AFE4490_SPI_SCLK_GPIO_CLK    RCC_AHB1Periph_GPIOB
#define AFE4490_SPI_SCLK_SOURCE    GPIO_PinSource13
#define AFE4490_SPI_SCLK_AF          GPIO_AF_SPI2

#define AFE4490_SPI_SOMI_PIN       GPIO_Pin_14 //PB14
#define AFE4490_SPI_SOMI_GPIO_PORT GPIOB
#define AFE4490_SPI_SOMI_GPIO_CLK    RCC_AHB1Periph_GPIOB
#define AFE4490_SPI_SOMI_SOURCE    GPIO_PinSource14
#define AFE4490_SPI_SOMI_AF          GPIO_AF_SPI2

#define AFE4490_SPI_SIMO_PIN       GPIO_Pin_15 //PB15
#define AFE4490_SPI_SIMO_GPIO_PORT GPIOB
#define AFE4490_SPI_SIMO_GPIO_CLK    RCC_AHB1Periph_GPIOB
#define AFE4490_SPI_SIMO_SOURCE    GPIO_PinSource15
#define AFE4490_SPI_SIMO_AF          GPIO_AF_SPI2

#define AFE4490_SPI_STE_PIN          GPIO_Pin_12 //PB12
#define AFE4490_SPI_STE_GPIO_PORT    GPIOB
#define AFE4490_SPI_STE_GPIO_CLK    RCC_AHB1Periph_GPIOB

.c文件，SPI设置
void AFE4490_Init(void) //SPI设置
{
  GPIO_InitTypeDef GPIO_InitStructure;
  SPI_InitTypeDef  SPI_InitStructure;

  /* Enable the SPI periph */
  RCC_APB1PeriphClockCmd(AFE4490_SPI_CLK,ENABLE);

  /* Enable SCLK, SOMI, SIMO ,and STE GPIO clocks */
  RCC_AHB1PeriphClockCmd(AFE4490_SPI_SCLK_GPIO_CLK| AFE4490_SPI_SOMI_GPIO_CLK | AFE4490_SPI_SIMO_GPIO_CLK, ENABLE);
  RCC_AHB1PeriphClockCmd(AFE4490_SPI_STE_GPIO_CLK, ENABLE);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  /* SPI SCLK pin configuration */
  GPIO_InitStructure.GPIO_Pin = AFE4490_SPI_SCLK_PIN;
  GPIO_Init(AFE4490_SPI_SCLK_GPIO_PORT, &GPIO_InitStructure);

  /* SPI SOMI pin configuration */
  GPIO_InitStructure.GPIO_Pin = AFE4490_SPI_SOMI_PIN;
  GPIO_Init(AFE4490_SPI_SOMI_GPIO_PORT, &GPIO_InitStructure);

  /* SPI SIMO pin configuration */
  GPIO_InitStructure.GPIO_Pin = AFE4490_SPI_SIMO_PIN;
  GPIO_Init(AFE4490_SPI_SIMO_GPIO_PORT, &GPIO_InitStructure);


  GPIO_PinAFConfig(AFE4490_SPI_SCLK_GPIO_PORT, AFE4490_SPI_SCLK_SOURCE, AFE4490_SPI_SCLK_AF);
  GPIO_PinAFConfig(AFE4490_SPI_SOMI_GPIO_PORT, AFE4490_SPI_SOMI_SOURCE, AFE4490_SPI_SOMI_AF);
  GPIO_PinAFConfig(AFE4490_SPI_SIMO_GPIO_PORT, AFE4490_SPI_SIMO_SOURCE, AFE4490_SPI_SIMO_AF);

/* SPI configuration -------------------------------------------------------*/
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_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_BaudRatePrescaler_256;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_Init(AFE4490_SPI, &SPI_InitStructure);
  /* Enable SPI2  */
  SPI_Cmd(AFE4490_SPI, ENABLE);

  GPIO_InitStructure.GPIO_Pin =AFE4490_SPI_STE_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(AFE4490_SPI_STE_GPIO_PORT, &GPIO_InitStructure);
  GPIO_SetBits(AFE4490_SPI_STE_GPIO_PORT, AFE4490_SPI_STE_PIN);


GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  GPIO_SetBits(GPIOB, GPIO_Pin_11);
  GPIO_SetBits(GPIOB, GPIO_Pin_11);

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC,ENABLE);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOC, &GPIO_InitStructure);
  GPIO_SetBits(GPIOC, GPIO_Pin_5);

/* CPIO clksel reset */
  delay(1000);
  GPIO_ResetBits(GPIOC, GPIO_Pin_5);
  delay(1000);
  GPIO_SetBits(GPIOC, GPIO_Pin_5);

}

uint8_t AFE4490_SendByte(uint8_t byte)
{
  AFE4490Timeout = AFE4490_FLAG_TIMEOUT;
//等待发送信号寄存器为非空，然后发送一个字节到spi总线上
  while (SPI_I2S_GetFlagStatus(AFE4490_SPI, SPI_I2S_FLAG_TXE) == RESET)
  {
if((AFE4490Timeout--) == 0) return AFE4490_TIMEOUT_UserCallback();
  }
//只管发送即可
  SPI_I2S_SendData(AFE4490_SPI, byte);
  AFE4490Timeout = AFE4490_FLAG_TIMEOUT;
//等待接收信号寄存器为非空，然后从spi总线上接收一个字节
  while (SPI_I2S_GetFlagStatus(AFE4490_SPI, SPI_I2S_FLAG_RXNE) == RESET)
  {
if((AFE4490Timeout--) == 0) return AFE4490_TIMEOUT_UserCallback();
  }
//需要返回一个字节
  return (uint8_t)SPI_I2S_ReceiveData(AFE4490_SPI);

}