后来查了查C6711,B,C,D,的PDF,里的的Terminal Functions里的CLKS1,DR1引脚说明有这么一句话:On the C6711C/11D device, this pin does not have an internal pulldown (IPD). For
proper C6711C/11D device operation, the CLKS1 pin should either be driven
externally at all times or be pulled up with a 10-kΩ resistor to a valid logic level.
Because it is common for some ICs to 3-state their outputs at times, a 10-kΩ
pullup resistor may be desirable even when an external device is driving the pin.
我按说法把这两脚接了个10K的上拉电阻,MCBSP1还的DX1还是不正常!