I'm using an ad9954 to output 122MHz as in the exemple in the datasheet. I want first ensure that the dds acceipt intruction byte and data word. So I write to the adresse 0x01 thid data 0x0000A4. I'm using a 20 MHz crystal as refclk, so according to my programming word SYNC_CLK should be at 100MHz , but no it is juste at 5MHz. Clearly the dds doesn't use the multiplier factor and I don't know what could be reason.
I send data from a fpga using the same clock as the sclk of the dds. In my process, I set the reset pin and send in MSB format the word 0x010000A4 and at the and I set io_update pin but nothing's happened. I use a design looks like the one attached( it's a design for ad9951EP).
Could you tell me please what should ?