Hi Dave,

>        I was away for a while, but I am now back. Don't matter, nobody knew
>me...:(

We're glad you're back anyways...

>        I am back because I need your help. I have an ASM file that contains:
>
>        sublw   .3
>
>and it is not working properly. When I am replacing it with addlw 0xFD,
>everything is working! I though the assembler was translating a sublw
>into the right addlw?! Is it the same opcode?

Dmitry answered your question.

>Another BIG problem:
>
>        I am reading a byte 0xAD in EEPROM, with:
>
>EEREAD  bsf     STATUS,RP0
>        bsf     EECON1,RD
>        bcf     STATUS,RP0
>        movf    EEDATA,w
>        return
>
>
>In my main program I am doing the following code:
>
>        call    EEREAD
>        btfsc   w,2
>        goto    OK
>        ....
>OK      "Send to LCD that I have been here"

The problem is, you aren't "btfsc w,2" - you are actually executing:

  btfsc INDF, 2

"w" is evaluated to Zero in MPASM and Register Zero is actually "INDF" (the
register pointed to by FSR.

In this case, you can either use the working code exchange:

  btfsc w,2

with

  andlw 4                       ;  Isolate Bit 2
  btfss STATUS, Z

But, I would stick with the working example (not only is it easier to
understand, but it doesn't change the value in "w").


Good luck,

myke

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