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AM2432: on-chip SRAM utilization

Part Number: AM2432

Hello,

For a new project using SPI boot, I am checking whether or not our application fits in SRAM in AM2432.

In my review, the first 512KB(2 banks) is reserved for SBL, the last 256KB(1 bank) is reserved for IPC, and 1 MB (4 banks) is used for the Profinet stack. As a result, only 256KB(1 bank) is available. if my understanding of this memory usage is wrong, please correct me. We need more space and don't want to add external SRAM. so, I would like to know how I can make more space in SRAM for application. Can you share your knowledge and idea on this?

Regards

Moonil

 

  • Hi Moonil,

    The SBL only uses the first 256KB during the SBL time and it will be released to application later. Yes, you cannot use it for store code or initialized data, but it can be used as uninitialized data (like data buffers). The SysFW and IPC will use the last 128KB. That leaves 2MB - 128KB (SysFW & IPC) -1MB (Profinet) = 896KB for your application. Keep in mind, that there is 128KB to 256 KB TCM available too.

    Best regards,

    Ming 

  • Hi Ming,

    Thank you for your kind explanation. I would like to confirm the reserved areas in OCSRAM  with you again.

    According to SDK document in the link below,

    https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/latest/exports/docs/api_guide_am243x/MEMORY_MAP.html

    "It can be seen that the initial 512 KB of MSRAM is reserved for SBL usage. This is for a combined bootloader image which contains the System Controller Firmware (SYSFW) to be loaded into the DMSC Cortex M3 and the SYSFW Board Configuration data as well."

    "Also in the last 128 KB of memory used by DMSC during run time, initial 80 KB gets free if a security handover happens. The last 48 KB still will be used by DMSC."

    I agree the area for SBL will be released to application later, but the size of the reserved area itself seems different from your explanation. Can you clarify this again?

    Regards,

    Moonil

  • Hi Moonil,

    The description in https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/latest/exports/docs/api_guide_am243x/MEMORY_MAP.html is the most up to date. The SBL initial usage is 512KB not 256KB. The last 128KB usage will eventually released except the last 48KB which will be permanently used by the SYSFW. This will give you even bigger usable on-chip memory 2MB - 1MB - 48KB = 976KB.

    Sorry for any confusion!

    Best regards,

    Ming