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TMS320C6748: NOR Flash Compatibility

Part Number: TMS320C6748

Hi team,

For years my customer was using the DSP 6748 with a NOR FLASH Numonyx Axcell P30 and all is great. However, the new board is using MT28EW01GABA and I am wondering if this NOR FLASH is compatible with the 6748?

Can you confirm if it is compatible and the DSP can boot from the new NOR Flash?

Thank you.

  • Hi,

    I'm looking into this question. Is the NOR flash being used to boot?

    I've seen inconsistencies with the support of a RESET command between different memories with other processors. I'll be looking at that first. Should have something within a couple days.

    Regards,
    Mark

  • Thank you Mark. Yes, it will be used for booting the DSP.

  • Hi Mark,

    Any update on this? It's very important at my customer.

    Thank you.

  • Hi,

    I did some digging, and I cannot say that the MT28EW01GABA NOR flash will be a suitable replacement for the P30 NOR Flash. I don't have the bootROM source code so cannot confirm.

    My concern is if the BootROM software sends any commands to the NOR flash before a read.
    Specifically, commands like "0xFF" on the P30 - Write 0xFF to set to the Read Array state.
    This command is not defined for the Micron MT28EW01GABA NOR Flash, and I don't know how the Micron device would respond.

    Another possible significant difference is the read latency. I don't know the GPMC register settings used during the BootROM, but if it is tailored to the timings of the P30 NOR, then it might be a little fast for the MT28EW01GABA.
    P30 Address to output valid = 65ns
    MT28EW01GABA Address valid to output valid = 95ns
    Hopefully the software was written to work with the slowest read latency. Or maybe it queries the CFI data. I do not know, but I can ask the team.

    If the customer already has this device on their hardware, and they managed to write a boot image into it, then they using some debugging tools to see how far the process gets.

    There is a debug GEL file to see how far the bootloader got. Refer to 4 Debugging Bootloader in SPRACM8 - OMAPL138/C6748 ROM Bootloader Resources and FAQ

    Alternately, after an attempted boot, they can connect to CCS without running any kind of initialization GEL file to see where the program counter is or to use the memory window to study writes and reads to the GPMC address space with the memory window and with a logic analyzer/scope.

    Could also use a logic analyzer to see if any commands are sent to the NOR flash by the BootROM (like the 0xFF "read array" command).

    I'll check if there is any additional advice from the team.

    Regards,
    Mark