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Boot section communication of F283xD

Raja Saha94
Intellectual 575 points

Other Parts Discussed in Thread: TMS320F28377D, CONTROLSUITE

Hi all,

This is a generic query on C2000 processor.

I want to boot my processor ( F283xD) on SCI-A port. Now if my Trans receiver IC ( say ISO-35) is configured in only receive enable mode, will it work, i.e. the downloading will be successful?. 

Does processor also responds (i.e. transmit, like hand shaking) while boot loding operation is going on?

Please help.

  • 0
    TI__Guru 57255 points

    Hi,

    Please see Chapter 3 of the F2837xD's Technical Reference Manual (TRM) for more information on the boot flow:
    http://www.ti.com/lit/spruhm8

    Figure 3-11 of the current TRM (spruhm8c) and the text surrounding it will particularly be helpful.

    Put briefly:
    If the device's boot mode pins are set in SCI-boot-mode, the device will boot from SCI.  It will then wait for the data to come in via GPIO84 and GPIO85 (the default options for SCI boot mode) in the correct format.  Once all the program data is sent in, the MCU will attempt to run the code that it received.

    Hopefully this helps!


    Thank you,
    Brett

  • 0 in reply to Brett Larimore
    Intellectual 575 points

    Thanks Brett.

    yes your reply was quite helpfull.

    My doubt was whether the processor or C28x application code does response back something to host while boot mode downloading is happened through SCI. 

    I believe the answer is yes after reading TRM.

    I asked this doubt as I did a mistake in my control card ( based on TMS320F28377D), where I did not put any pull up resistor to my transmit (SCITXDA) which is going to my trans receiver (ISO-35, I used here for SCI transmission), hence I was in intention that data will not be able to transmit from processor at this time of boot downloading.

    However after going through the flow chart depicted in fig 3-11 ( page no 556 of TRM rev C), it seems to me that it itself makes the e RX & TX pin with pull up. Hence there should be any problem in boot mode communication.

    Please correct me if my assumption is wrong.

    Regards

    Raja Saha

  • 0 in reply to Raja Saha94
    TI__Mastermind 32995 points
    Hi Raja,
    In SCI Boot Mode, the C28x does respond back to every character that it receives. This is so that the processor which is sending the data to the SCI Boot loader can ensure correctness as well as not overflow the SCI Buffer on the C28x.

    The C28x will send characters back on its SCITX pin.

    sal
  • 0 in reply to Sal Pezzino
    TI__Guru 57255 points

    Hi Raja,

    I would recommend looking at the BootROM source in controlSUITE if you wish to look into the details:
    \controlSUITE\libs\utilities\boot_rom\F2837x_revb\revb_rom_sources\F2837x_bootROM\cpu01-bootROM\source\

    Please note that it does not appear that pull-ups are enabled in SCI boot mode (GPxPUD).  I have made a request to fix the SCI Boot flowchart in the TRM.

    As soon as SCI boot mode starts, the SCI will take control of the GPIO and will only output what is sent through the SCI (and output the idle output when transmitting nothing).  As a result, I'm not sure you'll have an issue.  Some of this depends on your system though.


    Thank you,
    Brett