请教关于flash w25x16的读取

zhengchao20105 · 发表于 2012-7-1 18:38:14

SPI_sendreceive(u8 dat)
{

    GPIOA->ODR&=0XFFFB;
    while((SPI1->SR|1<<1)==0)
    {
        retry++;
        if(retry>100)retry=0;
    }
    SPI1->DR=dat;
    GPIOA->ODR|=0X0004;
    retry=0;
    GPIOA->ODR&=0XFFFB;
    while((SPI1->SR|1<<0)==0)
    {
         retry++;
        if(retry>100)retry=0;
    }
    dat=SPI1->DR;
    GPIOA->ODR|=0X0004;
    return dat;
}
SPI_sendreceive(0xFF);
为什么读取的时候都会发送0xff,找了w25x16的datasheet，也没有找到原因？