28335与AD7656，急

haixin wang

您好，

我dsp通过cs6读取ad7656的测量值，硬件电路中dsp的read信号和cs6信号直接与AD7656连接，数据线一一对应。开始读数据时，对于直流量比较正常，但是读了3-4分钟时，读取的直流量发生了较大幅度的波动，利用示波器测量AD7656的输入信号与基准信号都很稳定。感觉是程序中有问题，仔细核对了程序中关于AD7656的时序，都很正常，感觉是不是xintf中配置有问题？如下：

EALLOW;
    XintfRegs.XINTCNF2.bit.XTIMCLK = 1;
    // No write buffering
    XintfRegs.XINTCNF2.bit.WRBUFF = 0;
    // XCLKOUT is enabled
    XintfRegs.XINTCNF2.bit.CLKOFF = 0;
    // XCLKOUT = XTIMCLK/2
    XintfRegs.XINTCNF2.bit.CLKMODE = 1;

    // Zone 0------------------------------------
    // When using ready, ACTIVE must be 1 or greater
    // Lead must always be 1 or greater
    // Zone write timing
    XintfRegs.XTIMING0.bit.XWRLEAD = 3;
    XintfRegs.XTIMING0.bit.XWRACTIVE = 7;
    XintfRegs.XTIMING0.bit.XWRTRAIL = 3;
    // Zone read timing
    XintfRegs.XTIMING0.bit.XRDLEAD = 3;
    XintfRegs.XTIMING0.bit.XRDACTIVE = 7;
    XintfRegs.XTIMING0.bit.XRDTRAIL = 3;

    // double all Zone read/write lead/active/trail timing
    XintfRegs.XTIMING0.bit.X2TIMING = 1;

    // Zone will sample XREADY signal
    XintfRegs.XTIMING0.bit.USEREADY = 1;
    XintfRegs.XTIMING0.bit.READYMODE = 1;  // sample asynchronous

    // Size must be either:
    // 0,1 = x32 or
    // 1,1 = x16 other values are reserved
    XintfRegs.XTIMING0.bit.XSIZE = 3;

    // Zone 6------------------------------------
    // When using ready, ACTIVE must be 1 or greater
    // Lead must always be 1 or greater
    // Zone write timing
    XintfRegs.XTIMING6.bit.XWRLEAD = 3;
    XintfRegs.XTIMING6.bit.XWRACTIVE = 7;
    XintfRegs.XTIMING6.bit.XWRTRAIL = 3;
    // Zone read timing
    XintfRegs.XTIMING6.bit.XRDLEAD = 3;
    XintfRegs.XTIMING6.bit.XRDACTIVE = 7;
    XintfRegs.XTIMING6.bit.XRDTRAIL = 3;

    // double all Zone read/write lead/active/trail timing
    XintfRegs.XTIMING6.bit.X2TIMING = 1;

    // Zone will sample XREADY signal
    XintfRegs.XTIMING6.bit.USEREADY = 1;
    XintfRegs.XTIMING6.bit.READYMODE = 1;  // sample asynchronous

谢谢，急

10 年多前