I encountered a problem when I used the AD9776A. In my design, the reference clock was 120Mhz, the ADC clock was 480Mhz, the VCO clock was 1920M and the PLL display was locked. I use 15Mhz sine wave and cosine wave as input signal, my input data rate is 120Mhz, the TXENABLE signal keeps high level and the SYNC signal keeps low level, but there is no signal in the output part. Which part should I check? Here is the value of my register.