Dave,

The beauty of the 18 series is... NO BANKING WORRIES.

  *
  |  __O    Thomas C. Sefranek   WA1RHP@ARRL.NET
  |_-\<,_   Amateur Radio Operator: WA1RHP
  (*)/ (*)  Bicycle mobile on 145.41, 448.625 MHz

http://hamradio.cmcorp.com/inventory/Inventory.html
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> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of David Duffy
> Sent: Sunday, February 16, 2003 8:19 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [PIC]: Stupid newbie PIC question
>
>
> Neil wrote:
> >Today is the first day of programming the PIC for me, so forgive
> me if I'm
> >asking something that's stupid or has been answered a zillion times. I
> >have checked over the various bits of documentation and examples I've
> >found and according to what's going on, the code isn't setting the
> >TRISA/B/C ports as they should!
> >
> >I'm using MPLAB version 6.10.0.0 with an 18F252, and here's my code
> >snippet:
> >
> >         movlw   PORTA_IN        ; Get port A's input setting
> >         movwf   TRISA           ; Set up appropriate tristating
> >
> >; Now port B
> >
> >         movlw   PORTB_IN        ; Get port B's input setting
> >         movwf   TRISB           ; Set up appropriate tristating
> >
> >; Now port C
> >
> >         movlw   PORTC_IN        ; Get port C's input setting
> >         movwf   TRISC           ; Set up appropriate tristating
> >
> >PORTA_IN = 0x40
> >PORTB_IN = 0x01
> >PORTC_IN = 0xb8
> >
> >I have verified that W is getting loaded with the values above (through
> >the IDE/debugger). When I read the tristate registers for each
> port, I get
> >this:
> >
> >TRISA = 0x00
> >TRISB = 0x81
> >TRISC = 0xB8
> >
> >The TRISA/B/C ports *ARE* changing, but TRISA/TRISB aren't coming up with
> >the right values. Any idea what I'm doing wrong? Thanks in advance!
>
> I've not looked at the 18Fxx but the TRIS registers are in bank 1 normally
> so you'll have to do something like this:
>
> bsf             rp0             ;select register bank 1
> movlw           0x81            ;get the setting
> movwf           trisc           ;copy it to the tris register
> bcf             rp0             ;back to register bank 0
>
> The ports themselves (in bank 0) are the same address as the tris
> registers, only up in register bank 1. It's an easy mistake to make.
> David...
> ___________________________________________
> David Duffy        Audio Visual Devices P/L
> U8, 9-11 Trade St, Cleveland 4163 Australia
> Ph: +61 7 38210362   Fax: +61 7 38210281
> New Web: www.audiovisualdevices.com.au
> ___________________________________________
>
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