MX6Q Custom Board : DDR3 ODT Settings & Bypass LDO

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

MX6Q Custom Board : DDR3 ODT Settings & Bypass LDO

1,223 Views
ottawa-imx6
Contributor IV

Hello everyone,

I am trying to optimize power and thermal on a custom MX6D board since it is running a little bit too hot for me and am interested in hearing about other peoples results.

Currently I am running mainline 3.14.1 on a custom mx6D board with 2GB of MT41K256M16HA-125E.

This week, I tried two things in an effort to cool things down a little bit.

1. Modifying the ODT Settings  based on app note 4579.  http://cache.freescale.com/files/32bit/doc/app_note/AN4579.pdf.

This states that power savings of up to 40% can be seen by optimizing this value.

I have updated the following  (for P0 and P1) to see if any change was evident:

DATA 4, MX6_MMDC_P0_MPODTCTRL, 0x00022227

to

DATA 4, MX6_MMDC_P0_MPODTCTRL, 0x00000007

but I do not see any changes at all.

Are there other modifications required for this change to take effect? I was surprised that there was no difference since everything I have read stated that this would have an effect.

2. Next, I have also tried to switch to using my external PFuze regulator and disabled the internal LDOs by putting the system in LDO Bypass mode. Everything boots up fine using VCORE 1.1V, and VSOC 1.2V andI had to disable cpufreq to get this working since I have not implemented the voltage scaling yet.
In this case however, I do not see any thermal or power improvements either. I was expecting things to cool down a little by using an external pmic.

Does anyone have any experience or thoughts on these two things or any other methods of improving the thermal performance of a custom board using software methods?

Thanks!

Brent

Labels (2)
0 Kudos
5 Replies

538 Views
AnsonHuang
NXP Employee
NXP Employee

Hi, Brent

     When you see the ODT setting is indeed changed from 0x22227 to 0x7, can you measure the power consumption of DDR, such as DDR_1V5 on PFuse's output? There should be improvement of power number.

     By doing LDO_BYPASS, there must be power improvment either, as the current should be same, but the input voltage is lower from 1.375V to 1.1 or 1.2V, can you measure the average power consumption?

     Better to read the register after kernel bootup to confirm the changes are applied.

0 Kudos

538 Views
ottawa-imx6
Contributor IV

Great Ideas. Thank you! I will confirm and test further.

0 Kudos

538 Views
jamesbone
NXP TechSupport
NXP TechSupport

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

0 Kudos

538 Views
ottawa-imx6
Contributor IV

Thank you, but no it has not.
I am not able to verify these results yet and am not seeing differences with the ODT settings.

Still working on it.

0 Kudos

538 Views
YixingKong
Senior Contributor IV

Ottawa

This discussion is closed since no activity. If you still need help, please feel free to reply with an update to this discussion, or create another discussion.

Thanks,

Yixing

0 Kudos