DDR Stress Test - Question - why is it slow?

[maheshkumarkoda]

Hi community,

I am running DDR_Stress_test for my customized board and eventually i got some doubts, Please clarify.

Environment:

Tool - DDR_Stress_Tester_V1.0.0, Processor - i.MX6 Quadcore, DDR Frequency - 528 MHz, ARM core speed - 800MHz, DDR density - 2GBytes (4GB), Write leveling calibration - 0042

Mode - HID mode is used.

Questions:

1). Why is the DDR_Stress_test is very slow? each loop is taking approx. 5 minutes.

2). What difference it makes when case i). DDR start Frequency = end frequency and case ii). DDR start & end frequencies are different?

3). How many loops are recommended with case i and case ii (from question 2)? if not both cases, which case is highly recommended?

4). Why to repeat test with updated MMDC register values from calibration? & How many times shall I repeat this test(with calibrated values from previous test) to get final working reg. values?

5). Where can i find exact technical document to know in detail about DDR Stress Test? (I already have user and application guides from FS, like to know reason behind this test)

Please help, Thank you :smileyhappy:

[Yuri · Accepted solution]

Hello,

  Please look at my comments below.

1.

  One of the main purposes of the DDR test is to find problems - this require some time.

2.

  The Stress test allows to check system either for single working frequency or range of frequencies.

3.

  To test carefully it may be recommended to run the test during long time (at several hours).

4.

  Other purpose of the testing is finding optimal parameters;  in particular, calibration provides

optimal (delay) timings. Any settings are reasonable if the test is working successfully during long time.  

5.

Please use the following resources about the Stress test.

http://www.nxp.com/webapp/Download?colCode=FTF-SDS-F0170

https://community.nxp.com/docs/DOC-101708

https://community.nxp.com/docs/DOC-105969

https://community.freescale.com/docs/DOC-96412

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

Have a great day,
Yuri

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