Forum Discussion

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

Why is my PLL losing lock after i reconfigure it?

I was doing a PLL reconfiguration and changing only my M counter from 3 to 6. Every time I did it, my PLL would lose lock. Couldn't figure out why but after some digging I found the answer. Any ti...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Hello All ,

Actually , reset is not requried for the PLL reconfiguration

If a reset is asserted , all the settings of reconfiguration will be lost

For example , in the mif file , the initial phase of the PLL is 0

After the reconfiguration , the phase is increased by one

If a reset is asserted , the Phase of PLL will return to 0 , instead of the value that user has set

I have verified it on the Silicon Device

Regards ,

Samson