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Booting on 6713

Joaquin Gonzalez
Expert 1200 points

Hi to everyone,

I would like to know if it would be possible to boot a 6713 using a RAM (static or dynamic) memory placed in CE1.

The idea is to keep 6713 held in reset by an external DSP. This external DSP would load the RAM with the code (booloader) and then release the 6713 so it starts the booting process.

Will I have any problem if i do it this way?

I have read many app. notes about booting and they all talk about ROM devices, never RAM. Is there a reason for that?

 

Thanks in advance,

Nuba.

 

  • 0
    TI__Guru 62975 points

    Nuba,

    The datasheet describes the EMIF boot in a paragraph starting with the following:

    Datasheet said:

    Upon the release of internal reset, the 1K-Byte ROM code located in the beginning of CE1 is copied to address 0 by the EDMA using the default ROM timings, while the CPU is internally “stalled”.

    What that means is that the device will use the default asynchronous EMIF memory interface settings for CE1 to copy in the boot code.  In order for your RAM-boot system to work, the memory component must use the same interface as the default EMIF configuration.  Usually, asynchronous interfaces and RAM interfaces are not compatible.

    -Tommy

  • 0 in reply to tlee
    Expert 1200 points

    Hi Tommy,

     

    Where can I find the spec for ROM default timings?

     

    Thanks in advance

  • 0 in reply to Joaquin Gonzalez
    TI__Guru*** 125430 points

    See the EMIF Reference Guide.  For example, page 88 shows the definition of the CECTLn registers.  The MTYPE field gets chosen based on the configuration of pins HD[4:3].  The rest of the timings are shown in the register.  They are all set to the slowest possible values for compatibility with the greatest number of devices.

    If you have an async memory device (like an SRAM) then what you are doing should work.  As Tommy mentioned this will not work with synchronous interfaces like SDRAM.