AM335x: DDR configuration in Linux

matusan

Guru 10235 points

Other Parts Discussed in Thread: AM3352

Hello, TI Experts,

Our customer starts to product design with AM3352 and

design original board with Micron-DDR(MT41K512M16HA-125 IT:A).

They sent us a question about DDR configuration.

Question is

What file do we have to modify in PROCESSOR-SDK-LINUX-AM335X?

We found related the E2E-thread as below;

http://e2e.ti.com/support/arm/sitara_arm/f/791/p/482207/1737931#1737931

We also read wiki as below;

http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips

http://processors.wiki.ti.com/index.php/AM335x_DDR_PHY_register_configuration_for_DDR3_using_Software_Leveling

These wikis said "DDR configuration by using CCS (gel file)".

But we cannot find how to modify files in PROCESSOR-SDK-LINUX-AM335X.

I would appreciate if you tell us recommended way to modify files in PROCESSOR-SDK-LINUX-AM335X for DDR configuration when we design original board.

Best regards,

over 8 years ago

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi,

You should modify the u-boot sources:
board/ti/am335x/board.c
arch/arm/cpu/armv7/am33xx/ddr.c
arch/arm/cpu/armv7/am33xx/emif4.c

Best Regards,
Yordan

0 Biser Gatchev-XID over 8 years ago in reply to Yordan Kovachev

TI__Guru**** 393215 points

See this step-by-step tutorial: processors.wiki.ti.com/.../Sitara_Linux_Training:_Tuning_the_DDR3_Timings_on_BeagleBoneBlack

0 matusan over 8 years ago in reply to Biser Gatchev-XID

Guru 10235 points

Hi,

Thank you for your kindness.
I really appreciate your help.
This information is very helpful!

Best regards

0 Kaka over 8 years ago in reply to Yordan Kovachev

Guru 24520 points

Hi Yordan,

I have a question for the modification part. Does we need to modify the following files?
arch/arm/cpu/armv7/am33xx/ddr.c
arch/arm/cpu/armv7/am33xx/emif4.c
In my understanding, we need to modify the only following files.
ddr_def.h : github.com/.../arch-am33xx
board.c: github.com/.../am335x
I checked this file, but I could not understand the modification point.
If possible, would you please spefic the modification point?

Also does this point means the following directory?
github.com/.../

Best regards.
Kaka

0 Yordan Kovachev over 8 years ago in reply to Kaka

TI__Guru**** 161600 points

Hi Kaka,

I am not sure where these u-boot sources come from... They are different from TI SDK u-boot, as a matter of fact they differ from mainline u-boot as well.
The files I refer to are located in arch/arm/cpu/armv7/am33xx/

Best Regards,
Yordan

0 Kaka over 8 years ago in reply to Yordan Kovachev

Guru 24520 points

Hi, Yordon
Thank you for your comments .
I got it. By the way, would you please provide answer for my first question(ddr.c and emif4.c) in previous post?

Best regards.
Kaka

0 Yordan Kovachev over 8 years ago in reply to Kaka

TI__Guru**** 161600 points

Hi,

Actually no, the ddr.c & emif4.c files take the already defined register values from the header files & the board file and do the corresponding settings.

Best Regards,
Yordan

0 Kaka over 8 years ago in reply to Yordan Kovachev

Guru 24520 points

Hi Yordan,

Thank you for your comment.
I got it.

Best regards.
Kaka

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AM335x: DDR configuration in Linux