• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 32 subscribers
  • Views 337 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

LP-AM243: Retaining a variable in the RAM between warm resets of the main domain

AM2434: Retaining variables in RAM across warm reset.

Ahmad Alhindawy
Prodigy 60 points
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? 

  • 0
    TI__Guru* 89545 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 in reply to JJD
    Prodigy 60 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 in reply to Ahmad Alhindawy
    TI__Guru* 89545 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 in reply to JJD
    Prodigy 60 points

    Thank you a lot for your help.

  • 0 in reply to JJD
    Prodigy 60 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 in reply to Ahmad Alhindawy
    TI__Guru* 89545 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