topic Re: Error: failed during write leveling calibration in i.MX Processors

Error: failed during write leveling calibration

liqi_wu — Mon, 06 Jul 2020 07:36:41 GMT

hi,

We made some custom board with IMX6ULL chip and MT41K64M16-125 SDRAM,and encountered problems while doing ddr calibration on board by ddr_stress_tester_v3.00. There are calibration log as follow:

============================================

ARM Clock set to 528MHz

============================================
DDR configuration
DDR type is DDR3
Data width: 16, bank num: 8
Row size: 14, col size: 10
Chip select CSD0 is used
Density per chip select: 256MB
============================================

Current Temperature: 41
============================================

DDR Freq: 396 MHz

ddr_mr1=0x00000000
Start write leveling calibration...
running Write level HW calibration
MPWLHWERR register read out for factory diagnostics:
MPWLHWERR PHY0 = 0x000000ff

HW WL cal status: no suitable delay value found for byte 1
Write leveling calibration completed but failed, the following results were found:
MMDC_MPWLDECTRL0 ch0 (0x021b080c) = 0x001F0001
Write DQS delay result:
Write DQS0 delay: 1/256 CK
Write DQS1 delay: 31/256 CK

Error: failed during write leveling calibration

The script I used can make calibration success on official board IMX6ULEVK.

Hope you can give me some advice about what happen to my board.

Re: Error: failed during write leveling calibration

igorpadykov — Mon, 06 Jul 2020 09:04:55 GMT

Hi liqi

error may be due to board ddr layout : may be suggested to recheck

it using sect.3.4.1 DDR routing rules

Hardware Development Guide for the i.MX 6ULL Applications Processor

Best regards
igor
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Re: Error: failed during write leveling calibration

liqi_wu — Mon, 06 Jul 2020 09:24:50 GMT

hi igor,

Thank you for your quickly reply.

If so, how can I to configure the ddr registers manually to connect to DDR success?

Or it need to redesigning my board?

Re: Error: failed during write leveling calibration

liqi_wu — Wed, 27 Jan 2021 05:53:24 GMT

this issue is fixed. The root cause is the hardware design of my board. The power pin of the DDR chip missed the connection.