DDR stress test fails on imx6d based board

[anandmistryk]

Hi,

We are facing an issue with the DDR on our imx6d based board.

Out of the 10 boards of our first batch, one board is failing the ddr stress test. Rest all 9 boards pass the test.
We are trying to figure out the issue.

Our configuration
=================
We are using two chips of the MT41K512M16HA-125:A  on CS0 giving us 2GB with 32-bit data lines.

Our results
===========

We performed stress test using ddr-test-uboot-jtag-mx6dq.bin application for Uboot.

DDR frequecies were 528MHz, 532MHz and 198MHz.
On this particular board, it even fails at 198 MHz.

The stress test fails everytime at the 0x10000000 address

    === LOG (please see attached file for entire log) ===

    DDR Freq: 198 MHz
    t0.1: data is addr test
    Address of failure: 0x10000000
    Data was: 0x10000008
    But pattern  should match address
    Error: failed to run stress test!!!

Our doubt
=========
- is it a calibration issue, layout issue, or manufacturing issue?
- can anybody please tell us where to look at to diagnose the problem?

Thanks and Regards,

Anand Mistry

Original Attachment has been moved to: ddr_log.txt.zip

[igorpadykov]

"returns 0x10000008" - so bit 3 appearing as "1" can be easily tested with jtag and

obserwing waveforms with oscilloscope.

Best regards
igor

[RossMcLuckie]

Hi,

Since you have 9 out of 10 boards passing and the failing board fails on the first address 0x10000000, it seems likely you have a board, build error, the expected value is 0x10000000, but returns 0x10000008, which would suggest a possible issue with DATA03.

You can also look at the HDG which offers some help with board bring-up and debugging tips.

i.MX 6Dual Processors|Advanced 3D Graphics|NXP 

Regards

Ross