4DSP Products Technical support

Is there an example of what registers would need to be set up the AD9517 clock chip on the FMC112? I need to sample at 125 MHz using the internal VCO with no reference clock. I have been working with the chip and can see the reference clock, the VCO shows it is good at the monitor pin, but I am not getting any clocks out of the device.

This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.

Dear Paul,


I will close this topic in 24 hours without news from your side!


Best Regards,
Arnaud

Dear Paul,


Can you please let me know whether or not you are able to move forward?


Best Regards,
Arnaud

Dear Paul,


External reference using internal clock is one of the FMC112/FMC116 application mode. When you pass a 2 to the application, the whole chip set is configured for this given mode. That argument goes down to fmc116_cpld.cpp in a FMC116_cpld_init() function.


Indeed it looks like writing a 1 to register 0 of the CPLD is the write you need to do. As far as our reference design is concerned, the CPLD register range is located at the address of FMC112/FMC116 star start's address + 0x920.


I hope that helps, and please let me know if you need any more information about that before I close the topic.


Best Regards,
Arnaud

I followed the procedure that you have in the c file and it seems to work. The only issue not addressed is the CPLD setting. If I want to use the external reference with the internal VCO it looks like I write a 0x01 to location 0 of the CPLD. Is that correct?

Dear Paul,


Let me know if there is anything more I can do before to close this specific topic?


Best Regards,
Arnaud

Dear Paul,


We do not have a dedicated register table but we do have a software module in charge of configuring the AD9517 through the firmware. Check fmc116_clocktree.cpp in the FMC116App software source code. FMC116_clocktree_init() would be the reference function. Note that FMC116 and FMC112 are compatible in a software point of view.


I hope that helps!


Best Regards,
Arnaud