Dynamic reconfiguration of PLL

[tbalon]

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]

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]

Thanks for the info !