failed DDR DQS Auto calibration-LPC3250

[justinvil1103]

Hi,

We are running a DDR test and the following feature of the LPC3250 "DDR DQS Auto calibration" kept failing. We do not know what cause it to fail, any help would be greatly appreciated.

Thanks,

WJ

[vicentegomez]

Normally the DDR problems are due to hardware issues,

Do all the lines have the same impedance?

there are some application notes with recommendations about DDRs 

https://www.nxp.com/docs/en/application-note/AN10935.pdf

I hope this will help you.

[justinvil1103]

Hi Vicente,

We have a one-time calibration at boot up, what would happen if we turn the "Auto Calibration" off? or disable it?                                                                                                                                         

Thanks,                                                                                                                                                             WJ