PDCLK problem of EVAL-AD9957


I'm working with the AD9957 which is controlled by a DSP(TMS320 F2812). QDUC mode is selected. I can send control words to AD9957 sucessfully, and the SYSCLK is right, but the PDCLK pin does output the frequency I want, and the PDCLK is enabled. Plus, the Single Tone mode is right, that is I can get the wanted output wave.

Thanks very much!