STM32控制AD9837使用SPI发送控制字但AD9837没响应

使用STM32控制AD9837 ，使用SPI发送控制字，SPI的时序和发出的数据都看过，没有问题 。但是AD9837没响应。
STM32的代码如下：

void AD9837_SPI_Init( void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
  SPI_InitTypeDef SPI2_InitStruct;
   
   
//SPI 端口时钟初始化   
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);   
//SPI 片选使能初始化   
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE, ENABLE);

    /* Confugure SCK and MOSI pins as Input Floating */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 ;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_AF_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
   
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15|GPIO_Pin_14;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_AF_PP ;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
   
    //FSYNC 初始化
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8| GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOE, &GPIO_InitStructure);
   
    ADI_CS_HIGH_1;
    ADI_CS_HIGH_2;
   
//SPI2 时钟使能
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
   
    SPI_I2S_DeInit(SPI2);
   
    SPI2_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    SPI2_InitStruct.SPI_Mode = SPI_Mode_Master; //主模式
    SPI2_InitStruct.SPI_DataSize = SPI_DataSize_16b;
    SPI2_InitStruct.SPI_CPOL = SPI_CPOL_High;
    SPI2_InitStruct.SPI_CPHA = SPI_CPHA_1Edge;
    SPI2_InitStruct.SPI_NSS = SPI_NSS_Soft ;
    SPI2_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_64; //速录500K，1M也试过
    SPI2_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI2_InitStruct.SPI_CRCPolynomial = 7;
   
    //初始化
    SPI_Init(SPI2, &SPI2_InitStruct);
    //使能
    SPI_Cmd(SPI2,ENABLE);
   
    AD9837_SetRegisterValue(AD9837_REG_CMD | AD9837_RESET);
}
/***************************************************************************//**
* @brief Writes data to SPI.
*
* @param data - Write data buffer:
*               - first byte is the chip select number;
*               - from the second byte onwards are located data bytes to write.
* @param bytesNumber - Number of bytes to write.
*
* @return Number of written bytes.
*******************************************************************************/
void SPI_Write(uint16 data)
{
    while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET);
      
    SPI_I2S_SendData(SPI2, data);
}


AD9837.h和AD9837.C是使用ADI官网的例程文件。