DDR3 configuration for iMX6DL

[jaripeltonen]

Hi,

I'm developing SW for a device containing iMX6DL processor.
We are planning to replace the current SDRAM to a bigger one.
I have downloaded the DDR3 configuration aid tool, i.e.
MX6DL_SabreSD_DDR3_register_programming_aid_v2.2.xlsx from this link;
https://community.nxp.com/docs/DOC-105964 .

I am trying to figure out how to get all the configuration values correctly set for the new SDRAM.
I started by looking at the existing data in the Excel tool.
The memory component in the tool is MT41J128M16HA-15E.
I've also downloaded datasheet for this component; MT41J512M4_256M8_128M16_Rev_P.pdf .

Here are my questions regarding the values that I found not be consistent in the tool vs. datasheet;
tFAW:
- 50ns in Excel
- 45ns in datasheet p.79 (DDR3-1333, x16)

tCL, tRCD, tRP:
- 13.125ns in Excel
- 13.5ns in datasheet p.73 (DDR3-1333, -15E)

tRC:
- 50.625 in Excel
- 49.5ns in datasheet p.73

tRAS:
- 37.5ns in Excel
- 36ns in datasheet p.73

Could you please explain why the values in Excel tool are not according to datasheet?
It looks as if the values are those of the DDR3-1066 version of the SDRAM. Is that intentional?

Thanks & best regards,

Jari Peltonen

[jaripeltonen]

Hi Igor,

Thanks for your answer. Sorry for this late response, had to work on something else in between, now back on this SDRAM topic. A couple of additional questions just to clarify the chosen timing values.

1) What is the actual method of defining CWL and CL? Is it by searching for the correct tCK (2.5ns) in the Speed Bin table and choosing the CL and CWL pair that fulfills the currently used tCK value?

2) If SDRAM clock is 400MHz, should the timing values (tFAW, tCL, tRCD, tRP, tRAS) be set accordingly (DDR3-800)?

3) Isn't there a conflict if tCK=2.5ns (tCL=6, tCWL=5) and you choose timings (tFAW, tCL, tRCD, tRP , tRC and tRAS)
of tCK = 1.875ns (DDR3-1066)?

Best regards,
Jari

[igorpadykov]

Hi Jari

for new questions please create new thread.

Best regards
igor

[igorpadykov]

Hi Jari

yes intentional as it corresponds to processor max. MMDC frequency 528 MHz.

Similar explanation is given on

could IMX6Solo support DDR3-1600? 

Best regards
igor
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