AnsweredAssumed Answered

iMX6UL DDR Init and Stres Test

Question asked by Elizabeth Amyouny on Mar 27, 2018
Latest reply on Mar 28, 2018 by Yuri Muhin

I am using a Micron DDR3, PN MT41K64M16TW-107 on a custom design. Attached is the modified MMDC configuration script. The DDR parameters were modified from the MCIMX6UL-EVK spreadsheet.

 

After initializing the DDR w/o running the calibration (or stress test) I cannot R/W to any memory address.

 

If I initialize, followed by a calibration test the device fails at DQS calibration (see output below). However, despite failing, I am able to R/W to any memory address.

 

My questions are:

1. What is the calibration doing that despite failing, I can R/W to memory?

2. The eval board uses a Micron chip with an 1866 MT/s speed rating. The timing parameters inputted in the spreadsheet are set to the 800MT/s (400Mhz clock) rating. However, the speed bins (RAS,CAS, etc) are set to the 1866 MT/s parameters. Is this correct?

3. The eval board does not implement *any* address/command termination resistors. Is this because you are using the on-die termination? My custom design has discrete address/command termination resistors on the board. Is there a register setting I should be shutting off? Could this be why I am failing the calibration test?

 

Also for the record, the design fails the stress test immediately (see below).

 

//-------------------------------

 

DDR Freq: 365 MHz

t0.1: data is addr test

Address of failure(step2): 0x80000000

Data was: 0xffffffff

But pattern  should match address

Error: failed to run stress test!!!

 

//---------------------------------------------

    MMDC_MPWLDECTRL0 ch0 (0x021b080c) = 0x001F001F

Write DQS delay result:

   Write DQS0 delay: 31/256 CK

   Write DQS1 delay: 31/256 CK

 

Starting DQS gating calibration

. HC_DEL=0x00000000     result[00]=0x00000011

. HC_DEL=0x00000001     result[01]=0x00000011

. HC_DEL=0x00000002     result[02]=0x00000011

. HC_DEL=0x00000003     result[03]=0x00000011

. HC_DEL=0x00000004     result[04]=0x00000011

. HC_DEL=0x00000005     result[05]=0x00000011

. HC_DEL=0x00000006     result[06]=0x00000011

. HC_DEL=0x00000007     result[07]=0x00000011

. HC_DEL=0x00000008     result[08]=0x00000011

. HC_DEL=0x00000009     result[09]=0x00000011

. HC_DEL=0x0000000A     result[0A]=0x00000011

. HC_DEL=0x0000000B     result[0B]=0x00000011

. HC_DEL=0x0000000C     result[0C]=0x00000011

. HC_DEL=0x0000000D     result[0D]=0x00000011

ERROR FOUND, we can't get suitable value !!!!

dram test fails for all values.

 

Error: failed during ddr calibration

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