Hi NXP Team
Our customer have question about ddr stress test.
The Device is imx6QP.
OS is Yocto 2.1.
The Question link :
https://community.nxp.com/t5/i-MX-Processors/Need-to-disable-MMDC-arbitration-to-get-the-DDR-Stress-...
Please help to feedback it . Thanks.
(1) The customer try to settitng " MAARCR reset default = 0x514201F0"
(2) I would love to hear from the engineer who made this change why it is needed to make the script work.
NOTE that ALL other changes DO NOT MATTER. The DDR script works with the MAARCR value change. All your DDR scripts without the MAARCR value change result in DDR Stress Test errors.
(3) I've also tested with an MAARCR value of 0x54420010 (this leaves ARCR_SEC_ERR_EN set as per reset default, and it now follows the requirement of ARCR_DYN_JMP to be smaller than ARCR_DYN_MAX). Also with MAARCR set to 0x54420010 the 2GB DDR script works. I just used the online script (from the dropbox link) and added setting MAARCR to 0x54420010. NO OTHER CHANGES ARE REQUIRED!
(4) As a final step, I set MAARCR to the reset default, apart from bit 26 which disables MMDC arbitration, and this bit is indeed the key. When bit 26 of MAARCR is set (meaning MMDC arbitration is disabled) the DDR scripts work. With it left cleared (as reset default, meaning MMDC arbitration enabled), all your DDR scripts fail to complete the DDR Stress Tests.
(5) But, I really don't like making changes that do not have a good explanation, so I really would love to hear from whomever made this change in your organization.
Next, I added setting MAARCR to 0x54420010 in my script for the 1GB module, and also here this results in the DDR Stress Test to run just fine.
Do you have any idea or feedback about the some question and MAARCR reset default = 0x514201F0 is fail, but MAARCR reset default = 0x51420010 is running?
Thanks.
