Reconfigurable PLL

[Clicker]

Hello,

I'm desigining a reconfigurable PLL using Quartus 2 Mega Function
Wizard. I have been able to reconfigure the PLL to change frequency
from 150 Mhz to 33.33 MHz. Now I'm trying to run the other way. 33.33
MHz to 150 MHz.

Has anybody done something like this before for power savings.

Thanks.

 

[Clicker]

I should also mention that the trouble I'm getting into is while trying
to increase the frequency back to 150 MHz.

If anybody has design examples or anything of such sort will be very
helpful.

Thanks.

 

[vinkumia]

Hi,

I worked with the reconfigurable PLL few weeks ago. And we encountered
problems too. Eventually we got it working on the board. There was some
issues conserning change in M and N counters. According to Altera
errata sheet for the device there is a "bug" in that device. It also
listed a work around for the problem and it worked fine for us. It is
difficult to say without any details, if your problems have the same
source..

Vinkumia