Disappeaed a result of DDR Calibration test

[ko-hey]

Hi all,

My customer evaluate their board and try to fix DDR calibration values.

They tried several times in some boards and found some results is disappeared in calibration test.

i.MX6/7 DDR Stress Test Tool V3.00 

As you can see in calibration_ubnormal.txt, the test result of "loop ABS offset to get HW_DG_LOW" is lack.

Q1.

Is there any reason of the result ?

Q2.

Is there any possibility of somethings is wrong with the board ?

Ko-hey

[ko-hey]

Can anyone follow this question ?

Ko-hey

[gusarambula]

Hello Ko-hey,

My apologies. I'm inquiring if this is a known behavior and what would it mean, as I haven't seen this before. In the meantime, would you please share which i.MX processor you are using? And I would also like to confirm that this behavior occurs only in some of the boards, would you know how often (i.e. half of the boards or is it not as prevalent)?

Regards,

[ko-hey]

Hi gusarambula‌,

Thank you for reply.

We've used i.MX6SL and test with following tool.

https://community.nxp.com/docs/DOC-105652 

Ko-hey

[gusarambula]

Hello Ko-hey,

My apologies for the delay. Would you please let us know if you are seeing different calibration results when you do the same calibration on the same board? Or are they consistent between boards?

Sometimes the "loop ABS offset to get HW_DG_LOW" calibration won't be performed and thus won't be listed on the log.

Regards,