DVFS and DPS for AM5728

Michi Yama

Guru 10030 points

Other Parts Discussed in Thread: AM5728

Hi,

My customer would like to decrease the power consumption of AM5728.

I think DVFS and DPS are very useful for it. I have some qeustions for DVFS and DPS of AM5728. Please see the below.

1) How many customers do use the DVFS and DPS. Is it enough results for customer satisfaction?

2 Is the AM5728 performance influenced by using DVFS and DPS?

3) How evaluation is required to the system when DVFS and DPS is used?

4) Where is the sample code for using DVFS and DPS? I think Linux SDK supports both function. But I don't know the filename and its place.

Please give me your answer to my questions.

I appreciate your quick reply.

Best regards,

Michi

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

1. We cannot give such information here. Please talk with the local TI reps.
2. No, as long as OPPs are not changed.
3. I don't understand what you are asking here.
4. See processors.wiki.ti.com/.../Linux_Core_Power_Management_User's_Guide_(v4.1)

0 Michi Yama over 9 years ago in reply to Biser Gatchev-XID

Guru 10030 points

Dear Biser-san,

Thank you for your quick reply.

Regarding question2, I worry about performance decrease if DVFS and DPS is used. Do DVFS and DPS feature make performance decrease of AM5728?

Regarding question3, if I use DVFS and DPS feature with AM5728, How can I know its feature works well?

Regarding question4, I need samaple code for DVFS and DPS feature supported. Which folder can I find the sample code?

I appreciate your quick reply.

Best regards,
Michi

0 Michi Yama over 9 years ago in reply to Michi Yama

Guru 10030 points

Dear Biser-san,

Thank you for your support.

I found some source code in Linux SDK.

voltdm_omap.c ( ti-processor-sdk-linux-am57xx-evm-xx\board-support\linux-xxx\drivers\power\voltdm ) ---- I think this source is used for AVS(Store the value of efuse register to voltage domain). Is my understanding right?

But I don't know the sample code for DVFS and DPS. Can I find it in where?

I appreciate your quick reply.

Best regards,
Michi

0 Biser Gatchev-XID over 9 years ago in reply to Michi Yama

TI__Guru**** 393215 points

I have asked the PM experts to help with your last questions. They will post directly here.

0 Michi Yama over 9 years ago in reply to Biser Gatchev-XID

Guru 10030 points

Dear Biser-san,

Thank you for your support.

I have one more question regarding AM57xx.

According to the data manual, AM57xx supports only AVS class 0.
Does this mean DVFS is not supported for AM57xx device?

Please let me know.

Best regards,
Michi

0 Biser Gatchev-XID over 9 years ago in reply to Michi Yama

TI__Guru**** 393215 points

Please check the wiki link I posted above. Supported devices for each power management technique are listed there.

0 Michi Yama over 9 years ago in reply to Biser Gatchev-XID

Guru 10030 points

Dear Biser-san,

Thank you for your continuous support.

I understood that AVS class 0(smart reflex) and DVFS are different.

Also I understood J6/AM57xx support only two OPPs by DVFS. According to "Linux Core Power Management User's Guide" wiki that you pointed me, OPP_TURBO is not supported. However, as you know, J6/AM57 does not have OPP_TURBO mode. OPPs for J6/AM57xx are OPP_NOM, OPP_OD and OPP_HIGH. How should I think this meaning "not support OPP_TURBO"? Is "OPP_TURBO" typo for "OPP_HIGH"?

Please advise me.

I appreciate your quick reply.

Best regards,

Michi

0 Michael Erdahl over 9 years ago in reply to Michi Yama

TI__Genius 13505 points

Dear Yama-san,

"OPP_TURBO" is indeed a typo, and should have said "OPP_HIGH". Thank you for pointing this out- I corrected it.

Regards,
Mike

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DVFS and DPS for AM5728