DDR Stress tester V3.00 hung if set WALAT=1

torus1000 — Tue, 23 Jul 2019 05:01:18 GMT

Hi,

I ran DDR Stress tester V3.00 for our i.MX6D board but hung after setting WALAT=1.
Also see: https://community.nxp.com/message/1124054

DDR Stress tester V2.60 completed without any problems.

Is there any difference between each write leveling calibration?

I guess something modified in V2.91 or V2.92.

Can anyone help me?

Re: DDR Stress tester V3.00 hung if set WALAT=1

Yuri — Tue, 30 Jul 2019 06:36:04 GMT

Hello,

According to i.MX DDR Register Programming Aids :

The DDR stress test also has a feature whereby it evaluates the write leveling values returned from calibration and increments WALAT to 1 if the values exceed a defined limit. The DDR stress test informs the user when the Write Additional latency (WALAT) exceeds the limit and should be increased by 1, and reminds the user to add it back in the customer specific initialization script if required.

WALAT

00000000

WALAT: Write Additional latency. Recommend to clear these bits. Proper board design should ensure that the DDR3 devices are placed close enough to the MMDC to ensure the skew between CLK and DQS is less than 1 cycle.

So, it is not recommended to set WALAT with the Stress test. It is assumed to be done automatically.

Have a great day,

Yuri.

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topic DDR Stress tester V3.00 hung if set WALAT=1 in i.MX Processors

DDR Stress tester V3.00 hung if set WALAT=1

Re: DDR Stress tester V3.00 hung if set WALAT=1