Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

pll reconfiguration on cycloneIII

Dear all, My requirement is to have a pll that can be reconfigured on fly to 2 different frequency 100 MHz and 50 MHz. My input clock is 5MHz. I am using 2 ROM having the settings for the 2 fre...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I'm trying to use an altclkctrl to switch between two clocks but my fitter fails every damn time. I've tried various combination of clkin_p pins, PLL outputs, other global clocks... I've read the user guide and it says that what I'm doing is fine, so is it reasonable for the fitter to fail my design just on geometry and timing ground? Or am I missing something