Dynamic reconfiguration of PLL

tbalon 2019-09-13 15:45:39 UTC #1

Is it possible to control the parameters to one of the PLL's from verilog ? I know about the ice tool
for generating a PLL, but I want to have dynamic control over the frequency.

daveshah 2019-09-13 20:59:51 UTC #2

It's technically possible, using the SDI/SCLK/SDO pins (which connect to a 27-bit shift register in the PLL) and TEST_MODE set to 1, but I don't think anyone has tried this yet. The vendor simulation model (in icecube or radiant) has details of what the bits do, I don't think they are documented anywhere else.

tbalon 2019-09-15 15:20:34 UTC #3

Thanks for the info !

georgezip 2021-07-19 13:34:31 UTC #4

I have tried this but the documentation seems inconsistent and i could not make it work. Has anyone actually managed to do this yet?