I am now working a AD9957 project. I used ADF4360-6 to provide 619MHz REF_CLOCK,  I do not use ad9957 internal PLL,  The sync_clk is OK. I test the single tone mode is right, But when I use QDUC MODE ,there is no signal. I found when I set the profile register,the cci_ovfl will go high.  Need to emphasize when I Repeated configuration AD9957,sometimes the QDUC mode is OK, but most of the time,there is no signal,and the cci_ovfl is high.

    I want to konw what caused the cci_ovfl go high,is there any specific knowledge about ad9957 CCI.

    How can I solve this problem?