我在配置stm32f051r8上的SPI时遇到了问题。尽管我已经编写了全部初始化代码,但是我无法通过示波器看到时钟信号。我试图将PB13配置为时钟的备用功能,但是它没有起作用。
你能帮助我吗?非常感谢。
void spi_conf()
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
/* Enable SPI clock, SPI1 */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2,ENABLE);
/* SPI SCK, MOSI, MISO pin configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_15 | GPIO_Pin_14;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_1; // 10 MHz
GPIO_Init(GPIOB, &GPIO_InitStructure);
// Configure CS pin as output floating
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_0); // SPI1 SCK
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_0); // SPI1 MOSI
GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_0); // SPI1 MISO
/* SPI configuration ------------------------------------------------------- */
SPI_I2S_DeInit(SPI2);
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_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_Init(SPI2, &SPI_InitStructure);
SPI_SSOutputCmd(SPI2, ENABLE);
SPI_Cmd(SPI2, ENABLE);
}
int main(void)
{
spi_conf();
while(1)
{
}
}