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isp programming at89c51rd2

William Rojas

Hi

I am using the at89c51rd2 from atmel and I am a little bit confused on how to upload the firmware thru the UART.

As far as i understand you can use Atmel's "Flip" but you have to meet certain hardware conditions or you can do it by invoking the isp bootloader by setting BJLB BSB=0xFF, SBV=0xFC.

How do I set these values? i don't see the registers in the header.
Also, Is there another easier way to do this?

Thanks in advance.

Parents
  • 0 in reply to Jerry Huang

    I, fortunately, do not use Atmel, but do recall something posted several times that some Atmel chips come with one code meaning CAN ISP, another meaning USB ISP and another meaning UART ISP. DO check the datasheet for this detail and verify that chip and ISP method matches.

    Erik

Reply
  • 0 in reply to Jerry Huang

    I, fortunately, do not use Atmel, but do recall something posted several times that some Atmel chips come with one code meaning CAN ISP, another meaning USB ISP and another meaning UART ISP. DO check the datasheet for this detail and verify that chip and ISP method matches.

    Erik

Children
  • 0 in reply to erik malund

    Hi guys,

    First of all, thanks for your response.

    My idea was to try to clear the BLJB, set the BSB to 0xFF, set SBV to 0xFC (all this by software when i send a commnad to the micro) and then generate a reset; that way the micro will go into bootloader and now I can run flip to program the chip.

    I have been reading a little bit more and I think i will not be able to do this, i read somewhere that the BLJB value can be modified only in paralell programming mode. I guess I will have to meet the hardware conditions if I want to do this.

    Is there any other way that i can acomplish this without changint the hardware? right now the hardware does not have any connections to the
    !PSEN pin.

    Thanks

  • 0 in reply to William Rojas

    My idea was to try to clear the BLJB, set the BSB to 0xFF, set SBV to 0xFC (all this by software when i send a commnad to the micro) and then generate a reset; that way the micro will go into bootloader and now I can run flip to program the chip.

    I have been reading a little bit more and I think i will not be able to do this

    you should be able to do it, someone has done it.

    I will try to hunt up who, but have not much hope.

    When I published NoTouch and "the backdoor" for the Philips P89C51Rx2's someone did exactly this for the Atmels These, of course are moot by now since the NXP 'V' chips automatically go into ISP.

    I do not know if it will help you any, but NoTouch and "the backdoor" can both be found at the FlashMagic (esacademy) website

    Erik

  • 0 in reply to erik malund

    Hi Erik

    Thanks for the link. It is very helpfull. I will read it thoroughly and see. So far it seems to have all the information needed.

    Again, thanks a lot.

    Reards