> -----Original Message-----
> From: Olin Lathrop [SMTP:olin_piclist@EMBEDINC.COM]
> Sent: Thursday, February 28, 2002 12:34 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: [PIC]: Experimenting with F872 -- can't read from PORTA
> ???
>
> >>
>     movlw B'00111111'
>     movwf TRISA     ; Port A is all inputs
>     movlw B'00000110'
>     movwf ADCON1    ; Port A is all digital
>     movlw B'00000000'
>     movwf ADCON0    ; Turn off A/D
>     tris PORTB      ; Port B is all outputs
>     tris PORTC      ; Port C is all outputs
>
> loop:
>     movf PORTA,0    ; Grab data at port A
>     movwf PORTB     ; Dump to port B
>     goto loop
>
>     end
> <<
>
> For one thing, you've totally ignored bank settings.  You do need to pay
> attention to these.  Check out my DBANKIF and related macros if you want a
> more automatic way of setting the banks.  You can find them in
> STD.INS.ASPIC
> at http://www.embedinc.com/pic.
>
> Secondly, don't use the TRIS instruction.  I'm surprised the assembler
> didn't give you a warning.  This is an old instruction that is (has) being
> obsoleted.  Note that it's not in the list of instructions on page 136 of
> DS30292C.
>
> It looks like you may have programmed some old chips a long time ago.
> It's
> time to sit down and read the manual again for the chip you are using now.
>
Is there even one mid-range device that dosen't support the TRIS instruction
on ports A,B and C?

Mike

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