跪求stm32f103c8t6初始化spi2，sck没有时钟输出

小白来学习 · 发表于 2016-7-23 16:59:50

stm32f103c8t6初始化spi2，sck没有时钟输出，一直都是低电平，检查了好几遍，是不是配置问题？

void spi_Init()
{
SPI_InitTypeDef SPI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphResetCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI2,ENABLE);
//GPIO¿úÅäÖÃéèÖÃ//
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_SetBits(GPIOB,GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15);

/*Configure PA.4(NSS)--------------------------------------------*/
  GPIO_InitStructure.GPIO_Pin =GPIO_Pin_12;
  GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_SetBits(GPIOB,GPIO_Pin_12);
   /* SPI1 configuration */
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master; //主模式
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; //八位
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;//时钟空闲为高
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;//2跳变沿
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;//软件NSS
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;//256分频
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;//
  SPI_InitStructure.SPI_CRCPolynomial = 7;

SPI_Init(SPI2, &SPI_InitStructure);  //初始化
SPI_Cmd(SPI2, ENABLE); //使能
}

int main()
{
spi_Init();
while(1)
{
SPI_I2S_SendData(SPI2,0xff);
}
}
这是我用keil5的逻辑分析看到的。13pin为sck
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