01-22-2020 04:14 AM
Using the RFSoC RF Data Converter Evaluation User Interface we have made the external hardware changes to use an external clock. I see that I can write a config file to disable the PLLs, which I beleieve I should do, by setting Enable to 0 for each PLL. However I'm still confused about which paramters need to be set in the .config file. Which parameters need to be set to allow the use of an external clock?
01-22-2020 08:56 PM
I believe you are talking about *.cfg files that saved in "Config" folder.
You don't need to understand the format of .cfg file to use external clock.
Just fix the related capacitors on ZCU111 boards
RFSoC Evaluation tool GUI, set DAC/ADC Clock Source to use External clock source, click "Apply", Save the configuration file (so you don't need to all the same step next time) and you are good to go.
01-23-2020 02:18 AM
Configuring as you have I'm still getting this error. Any idea what the issue is?
Also in your above example you have bypassed the PLL but do not have an external reference clock, is this ok?
01-23-2020 04:00 PM
01-24-2020 06:55 AM
I'm a bit confused as I'm bypassing the PLL, so why does it need to lock? If I have a misunderstading here please clear it up for me because I think it might be the case. Can you give me an example of entries for the "Clocking Reference" and "Tile Clock Input" ? I think I must be misunderstanding quite a bit here.
01-25-2020 04:40 AM
Are you talking about using external clock source clocking the RFSoC instead of using on board LMK04208 clock output?
Leo pointed out you the way how to use the external clock source. You have to do some rework on ZCU111 board. Romoving the capacitors originally placed between the LMK04028 and RFSoC and mounting the capacitors to connect the SMA connectors and RFSoC.
Then you can choose the external clock as the clock source in the TRD GUI.