Hello lhanyong -- as a fellow 4DSP customer, I feel your pain. I, too, am struggling with the clocking of the interface between the FMC150 and the ML605. I simply want my baseband modulator to drive the DAC and my baseband demodulator to receive data from the ADC, which is about as simple an FMC150 application as I can envision. I am doing this by hacking the HDL Coder- generated VHDL to insert the DAC and ADC into the loop, to get things up and running in a simple loopback test.