changes to IBERT example break PLL lock

Question

I have the FMC Carrier Card rev C03 and the pz030 SOM. I can generate the example project at https://github.com/Avnet/hdl/tree/master/Projects/ibert and the PLL locks and has correct data rate. But if I change anything in the project, the PLL no longer locks. For example, in the example generated, I can open the IP block and change the data rate from 6.25 gbps to 2.0 gbps (keeping everything else the same - refclk at 250mhz, protocol and clock using refclk1) and after it builds, the PLL will not lock in the IBERT tool. I've tried TONS of combinations but nothing but the default settings will let the PLL lock. Is there an explanation for this? What am I doing wrong/not understanding?

Thanks in advance!

Dillon

Dillon1337 · Accepted Answer

The issue was that Vivado doesn't correctly re-generate the settings when you modify the IP from inside the example project. If I modified the IP, and then generated a new example project, it worked.