An issue about AD9212-40

Dear Engineers,

I encountered some issues about AD9212-40, could you please help check them

1、when CLK doesn't connect the common-mode voltage, what is voltage for pin9(clk-) and pin10(clk+), should it be 1.6V or 1.25V.

2、  how to start the test mode, and how to connect the circuit.

thanks.