I received a customer question about programming the AD9915. I searched EZ and provided links to the following threads:
- Parallel Mode Programming for AD99xx
- DDS(AD9915) Register Read Operation
- I have a problem to configure the AD9915
These did not answer his question. Here is the original question along with the follow up:
I am trying to write registers on the AD9915 using the parallel port. I can read registers fine with the parallel port. If I read register 0x08, I obtain the default value of 0x1C. To write registers, I am setting up the address and data lines as shown in figure 47 of the datasheet. I am setting the IO_UPDATE to active high as indicated on page 41. When I write a value of 0x01 to register 0x01, and I read the register back, the write did not occur because the output is 0x00.
The scenario I have encountered is mentioned in the following thread: "I have a problem to configure the AD9915". I have the board in parallel programming mode. The sync clock is not received. I am able to read a sample register. I am trying to use the register write interface to set the DAC CAL bit as mentioned on page 40 of the user guide. I tried to write a register and read the register to confirm that writes are successful.