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C5505 SPI boot

Does the C5505 SPI boot mode support using standard 8-bit wide SPI flash/eeprom devices? The data sheet only mentions 16-bit SPI boot, and I'm not sure if it's referring to the fact it checks the first two bytes for the correct signature of if the SPI memory device has to be organized as 16-bit wide words.

  • Hello mwh_invocon,


    Please see our C5505 bootloader appnote, Using the TMS320C5505/04 Bootloader:

     

    “The bootloader supports booting from an SPI EEPROM with the following requirements for the external

    device:

    • The device must support at least a 500 kHz SPI clock.

    • The device must be connected to SPI CS0 and act as an SPI slave.

    • The device uses 2 bytes (16 bits) for internal addressing (up to 64kB).

    • The device must have the capability to auto-increment its internal address counter to allow sequential reads from the device.

    • The device can be connected to either valid pin-mapping for SPI; there are two distinct pin-mappings available. The bootloader attempts to communicate on each SPI pin-mapping, one at a time."

     

    The SPI EEPROM should support 16-bit addressing and 8-bit data.

     

    These are the two SPI EEPROM chips that are in the C5505 EVM and C5505 eZdsp USBStick, respectively:

    ON Semi CAT25256 (formerly Catalyst)

    STMicro M95512-W

     

    Hope this helps,

    Mark

  • Thank you for the quick reply. Unfortunately we need a larger boot device than the serial devices can support, so we will have to use a parallel NOR flash or perhaps the MMC boot mode.

    Is MMC boot now supported? The data sheet (last revision Aug 09) says that it is not; does the bootloader document indicate this functionality is now supported?

    Thanks again.

  •  

    Hello,

    Please contact your local TI representative about using the C5505 bootloader with MMC/SD.

    Thanks,
    Mark

  • How big?

    As an aside, the C5506 supports 24-bit address serial devices for the bootloader, and those are available much larger than the internal memory of the DSP, so unless you need many, many  pages of code it should be enough.  There's basically one bootloader mode for 16-bit addresses and another mode for 24-bit addresses.  I haven't looked at the C5505 data sheets to see, but perhaps it supports the same two modes.