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我現在要用stm32驅動一個adc(ad5310),要把cs拉低，clk發送時鐘，data發生數據，數據在clk的上升沿取樣（原本是下降沿，現在在adc的clk前加了一個反相器），一共要發送16位數據，現在用I/O來模擬不行，用spi模塊也不行，為什么？下面是我寫的驅動程序，有人能看出問題出在哪里嗎？
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE,ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //spi_clk spi_mosi
GPIO_Init(GPIOA,&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //spi_cs
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOE, &GPIO_InitStructure);
SPI_InitStructure.SPI_Direction = SPI_Direction_1Line_Tx;
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_NSS_Hard
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI1,&SPI_InitStructure);
// SPI1 enable
SPI_Cmd(SPI1,ENABLE);
GPIO_ResetBits (GPIOE, GPIO_Pin_12);
SpiDelay(10);
while(SPI_I2S_GetFlagStatus(SPI1,SPI_I2S_FLAG_TXE)==RESET);
SPI_WriteByte(0x0f);
while(SPI_I2S_GetFlagStatus(SPI1,SPI_I2S_FLAG_TXE)==RESET);
SPI_WriteByte(0xff);
SpiDelay(10);
GPIO_SetBits (GPIOE, GPIO_Pin_12); |
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