C6657 and ZYNQ 7020 SPI problem

We have a self made board including DSP 6657 and ZYNQ 7020.

We debug the board by CCS5.5.

1, We use SPI_20160728.pjt (from STK_C6657, none modification) DSP self loopack ok.

2, We run our TestC6657McBSP_201603 .pjt

After entering MyC6657SPITest() function, DSP tries to send 0,1,...,255 to ZYNQ,

while ZYNQ receives 0, 1, 3, 3, 7, 7, 7, 7, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, 0xF, ...

(it seems once a bit of the data is set, it can't be cleared, so we send value 2 and received data is 3, because previously we send 1 and Bit0 is set).

When GPIO 28~31 and SPI MUX pins configured as GPIO, we can operate them and output either 0 or 1.

thanks, guys.TestC6657McBSP_201603.rarSPI_20160728.rar