AM2434: Retaining variables in RAM across warm reset.

Ahmad Alhindawy

Part Number: AM2434
Other Parts Discussed in Thread: SYSCONFIG

Tool/software:

Hello,

I am using the TMDS243EVM evaluation board for the AM2434 SoC. I want to retain a few variables' values across warm resets.

Is it possible to use a non-init section on the DDR RAM to achieve this? If so, does the SBL reset the DDR RAM or not ( OSPI_SBL, for example )?

Also, does a warm reset happen for all cores simultaneously, or can I reset one core individually?

8 months ago

0 JJD 8 months ago

TI__Guru* 92350 points

If you just want to retain a few variables, i would not recommend DDR, as this would be overkill for that purpose. You could use a small external memory, or the M4F core (with 256K RAM) has an isolation feature which could keep it alive across resets.

You cannot reset individual cores, warm reset affects all the cores, with the exception of the M4F if it is isolated

Regards,

James

0 Ahmad Alhindawy 8 months ago in reply to JJD

Prodigy 70 points

Thanks for your reply, James.

Yeah, the DDR will be overkill even if I use a small section of it, but I am restrained hardware wise so I want to use the board as is.

But is it possible to use the DDR for this purpose at all?

Also, for the M4F core solution, is it possible to read its memory directly from the R5F, or will it need IPC?

+1 JJD 8 months ago in reply to Ahmad Alhindawy

TI__Guru* 92350 points

Ahmad, the whole DDR will get reinitialized on each warm reset, there is no way to partition it to maintain a small portion of it. The M4F SRAM modules can be accessed by the R5F or A53s. Check the system memory map in the TRM

Regards,

James

0 Ahmad Alhindawy 8 months ago in reply to JJD

Prodigy 70 points

Thank you a lot for your help.

0 Ahmad Alhindawy 8 months ago in reply to JJD

Prodigy 70 points

Is there any example or how-to for reading M4F SRAM form other cores ?

I tried creating a region in the M4F SRAM but the memory configrator does not allow it to be sharable with other cores.

I am using code composer studio v20.

Again, thanks for your help.

0 JJD 8 months ago in reply to Ahmad Alhindawy

TI__Guru* 92350 points

Can you show your configuration? Do you mean the memory configurator in Sysconfig? You should be able to just read the address, not sure if you really need to make it sharable.

Regards,

James

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AM2434: Retaining variables in RAM across warm reset.