Linux/AM5728: CMEM maximum size for DSP

Sung-IL

Mastermind 31440 points

Part Number: AM5728

Tool/software: Linux

Dear Champs,

My customer is asking if CMEM can be increased to over 64MB and over 64MB in the CMEM can be allocated to DSPs.

It seems the allocated CMEM size for DSPs is 56MB and they want to increase this memory size for DSPs.

And also, I would like to check if there is any limitation in CMEM for DSPs and if allocated CMEM size should be for both DSPs? e.g. if 32MB is allocated for DSP1, should same 32MB be allocated for DSP2?

For the method how to extend CMEM size, I found below e2e and wiki sites, but please let me know if you have more helpful information.

Their SW is PSDK 04.00.00.04.

http://processors.wiki.ti.com/index.php/CMEM_Overview

https://e2e.ti.com/support/arm/sitara_arm/f/791/t/604490

https://e2e.ti.com/support/embedded/linux/f/354/t/621094?tisearch=e2e-sitesearch&keymatch=AM572x%20AND%20DSP%20AND%20CMEM

Thanks and Best Regards,

SI.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Rex Chang over 8 years ago in reply to Biser Gatchev-XID

TI__Guru 50170 points

Hi, Sung-Il,

You mentioned that it allocates 56MB for DSP. I think that is the application allocates it. CMEM is managed by the Linux. In the cmem dtsi file, the CMEM block size is default to 192MB. Application can allocate as much as it wants for DSP within CMEM block size.

Rex

0 Sung-IL over 8 years ago in reply to Rex Chang

TI__Mastermind 31440 points

Hi Rex,

Thanks for your response.
How about the limitation for DSPs? Should same CMEM memory size be allocated to each DSP? e.g. If 32MB in CMEM is allocated to DSP1, should same 32MB be allocated to DSP2 as well? is it possible to allocate 32MB of CMEM to DSP1 and 16MB of CMEM to DSP2?

Thanks and Best Regards,
SI.

0 Rex Chang over 8 years ago in reply to Sung-IL

TI__Guru 50170 points

Sung-Il,

CMEM is managed by and applies to Linux. Please take a look at the cmem.dtsi file. It is not defined per dsp. You can define multiple blocks and used by DSPs.

Rex

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Linux/AM5728: CMEM maximum size for DSP