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Application for PRAM ( CAN BUS Bootoader )

Marco Cortecchia

I'm working on a project where I need to upload the firmware from CAN BUS line ( automotive application ) . I must do it using the BOOTOLOADER started in "CAN Mode" .
My problem is how to say to uVision to compile the code and link it for PRAM destination , and say to uVision to upload it on PRAM other than intenal FLASH . Do anyone already worked on similar project ?

Thanks

  • 0

    I am not sure how to make the ULINK recognized that you want the VECSEG to be initialized to 0xE0. Additionally you are not allowed to debug (JTAG) while one of the bootloader modes is active (Chip restriction).

    So I assume you want to debug your CAN BSL code?

    If so, I would recommend that you make an addition but very short program in the internal Flash that sets the VECSEG to 0xE00000 and simply jumps there. This just makes sure that the hardware is in the proper state for your code that is running in the PRAM. Make sure you set NOVECTAB in the linker control.

    Here is an example of the jump program.

    $MODV2
$SEGMENTED
NAME    ?C_STARTUP
PUBLIC  ?C_STARTUP

Model   LIT     'NEAR'

?C_MAINREGISTERS REGDEF  R0 - R15
?C_STARTUP_CODE SECTION CODE 'ICODE'

VECSEG   DEFR   0FF12H

?C_RESET     PROC TASK C_STARTUP INTNO RESET = 0
?C_STARTUP:  LABEL   Model

  DISWDT  ; Disable watchdog timer
  MOV  VECSEG,#0E0h ; change reset vector after a reset
  JMPS #0E0h,#0000h ; jump to pram

?C_RESET        ENDP
?C_STARTUP_CODE ENDS
      END

    For the program (another project) that you want to run in the PRAM simply uncheck the use ONCHIP ROM and define a ROM memory at 0xE00000 with size of 0x800. Then add to the linker control VECSEC(0xE00000). In the "debug" options under "settings" change the startup to load the application into RAM. You don't load any flash driver.

    Hope this helps.
    -Chris

  • 0 in reply to Chris Wunderlich

    Thank You .
    Your suggestion is very fine .

    The idea to write a little program on FLASH that JUMP to my application on PSRAM is simple and work well .

    Your help , save me a lot of time . I hope to give You suggestion like this to You too in the future .

    Thank again