custom i.mx28 board fails ram init

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custom i.mx28 board fails ram init

Contributor I

We are making custom i.mx28 board without battery using nand. Bootlets fail at ram initialization and give "Undefined Ins" error at the end. We use DDR2 ram AS4C64M16D2 128Mb (datasheet is attached). Cpu voltages are fine.

We are using "imx-bootlets-src-10.12.01". We made some edits for battery configuration, we didnt change DDR2EmiController_EDE1116_200MHz() function. AS4C64M16D2 seems same with EDE1116 and we enabled ram test to check errors.

Our board's ram routing path lengths and groups:

                         MAX          MIN (mil)

DATA                857            833                 LDM, UDM, LDQS, LDQS, UDQS DQ0-15

CONTROL       980            971                 ODT0, CKE, CE0

CLK                  863            852

ADD                 1116          1092                BA0-2, CAS, RAS, WE, A0-A14

Bootlets memory test


Bootlets memory test without installing ram (i dont know if it makes sense)


How can we fix this errors, where we are doing wrong?

We found "mx28 ddr2 register programming aid" excel file. How to convert "RealView .inc file" to HW_DRAM_CTL00_ADDR array?

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NXP TechSupport
NXP TechSupport

Hi Enis

usage "DRAM Register Programming aid" tools can be found in i.MX6 example

p.10 presentation:

then run i.MX28 DDR test

i.MX28 DDR stress test

DDR good settings should be modified in DDR2EmiController_EDE1116_200MHz() function

Best regards



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Contributor I

Thank you for your answer, We fixed the problem and have a new problem.

We generate dram addr array using "DRAM Register Programming aid" with your instructions. We re-check cpu solders again and it works. Two dram addr arrays works. I think EDE1116 and AS4C64M16D2 are same. I check dram_size and dram_base in bootlets and uboot. And now uboot begins work, it doesnt write dram size to logs and hangs. Is there a solution?


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