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Observer cosminpanzaru1
Registered: ‎05-24-2018

Clocking Wizard Dynamic Reconfiguartion on ZCU102 board



I have a simple block design where based on some error measured, i am programing some registers of the MMCM through an AXI interface MfracMultiply value on register with offset 0x200 bit[25 : 16].

Basically i am following the following steps:

When i have a new value  for MfracMultiply  :


1. Write to Register 0x200 bit[25:16] new value

2. Check if locked at register 0x004 

3. If is locked write to Recofiguration Register 23 vale 0x0000 0003


The annoying thing is that as soon as a program Recofiguration Register 23  i loose lock for a short period of time (20 -> 80 us) and the output clock is flat. This makes my other blocks not to work properly.


I would like to ask if there is any other way not to loose output clock, or if i am doing something wrong ?

Thank you for your help.

0 Kudos
1 Reply
Registered: ‎02-09-2017

Re: Clocking Wizard Dynamic Reconfiguartion on ZCU102 board

Hi @cosminpanzaru1,


That is the correct behavior. the MMCM/PLL will always loose lock when your perform a DRP, because it needs to readjust the VCO frequency and also readjust the new output frequencies and phases.


What you should do is have the rest of your design to be dependent of the LOCKED pins. If the pin goes down, the rest of the logic should be in stand-by or reset.



Andre Guerrero

Product Applications Engineer

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