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TMS320F28377D SCI boot

Kens Alexandre
Intellectual 295 points
Other Parts Discussed in Thread: TMS320F28377D

Hi -

I recently purchased a Delfino TMS320F28377D controlCARD. I'm trying to set the device to SCI boot mode with SW1 and A:SW1 set in the following configuration. That's according to the documentation that I've read. 

A:SW1: Position1=0 (down) and Position2=1 (up)

SW1: Position1=0 (down) and Position2=0 (down)   ---------     I noticed that SW1 is up-side down, I tried both positions in the UP direction, as well. 

I've tried a number of different combinations with the switches and with different baud rates on my PC, but I'm not getting a response when I type the character "a". When I type the character "a", what I expect to see is "aa". I'm just seeing "a". By the way, I'm able to run the "sci_echoback_cpu01" example with no problem at different baud rates. I need some help. Thanks.

Kens

  • 0
    TI__Guru 57255 points

    Hi Kens,

    You have A:SW1 correct.  SW1 should be configured as Position 1 down (ON; pulls GPIO72 to low) and Position 2 up (OFF; allows GPIO84 to go high) for Boot-from-SCI mode.  This is the setting that the schematic suggests, but I notice that the infosheet is incorrect.  I will file a bug to get the infosheet corrected.

    ===

    However, I believe the root of your problem is that SCI boot mode expects to communicate via GPIO84 & GPIO85 by default.   My guess is that you are expecting to be able to use GPIO28 & GPIO29 (which go to the FTDI chip and then as USB signals to the USB-mini connector on the cCARD) directly.

    If you look in the TRM you can see that SCIBoot's IOOption1 is GPIO84&85 (see Section 3.20 of the current TRM). 

    This means you have two options:
    1) Use GPIO84 & GPIO85 instead.  If your platform for testing is the Experimenter's kit then editing the board or wiring in a transceiver are options.
    2) Change the boot mode to Get Mode and then, in your main flashed code, you can decide to call the bootloader for SCIBoot IOOption2 (in the bootROM) always or based on whatever you code in. 
    3) Change the boot mode to Get Mode and configure the OTP such that SCIBoot IOOption2 is called.  This is really only an option if you always want to boot from SCI or Parallel GPIO because you'll be overwriting your ability to boot from Flash (see Table 3-8 and Table 3-6 of the current TRM for more info).  This may be a decent option for debugging though.
    4) With an emulator connected (TRSTn = 1) you can have SCIBoot's IOOption2 boot mode get called.  I am not as familiar with this method and don't know the exact procedure, but know it exists.  I believe there are other forum posts which talk about this option.

    Hopefully this helps!


    Thank you,
    Brett

  • 0 in reply to Brett Larimore
    Intellectual 295 points

    Hi Brett,

    Thank you for replying to my post. Your response has helped a lot. I have tried step 4 above with the built-in emulator, and now the character "a" is being echoed back. Basically, I changed the boot mode from "SCI_BOOT" to "SCI_BOOT_ALTERNATE" and passed that to SCI_Boot(), which configures GPIO28 and GPIO29 as input and output pins, respectively. I will also try some of the other steps, but this has been very helpful. Thank you.

    Regards,

    Kens