Hi

This did not solve my GPIO problem.  Does anybody else have any advice?
I am trying a simple application for a 12C671 using MPLAB 3.40.  Trouble is I cannot seem to get the I/O's to toggle under the simulator (no change in the gpio SFR) by 

#define         DOUT    GPIO,2  ; SPI port DOUT signal
...
                bsf     STATUS,RP0        ; set file register bank to 1 
                movwf   OSCCAL            ; update register with factory cal value 
movlw   b'11001000'        ;Internal clk,prescaler to wdt
             movwf   OPTION_REG   ;
             movlw   b'00001001'        ;
             movwf   TRISIO               ; port 0, 3 are inputs, rest outputs

                bcf     STATUS,RP0        ; set file register bank to 0
                bsf     DOUT;
              bcf     DOUT;
...

Could somebody please point out my error to me?

Stefan Rousseau
stefanr@rrs.co.za
Technopark
Stellenbosch
South Africa



----------
From:  Kalle Pihlajasaari[SMTP:kalle@DEVICE.DATA.CO.ZA]
Sent:  Wednesday, May 06, 1998 12:29 PM
Subject:  Re: PIC 12C671 GPIO control

Hi Stefan,

> I am new to PICs so please excuse any blatant ignorance....  I am trying =
> a simple application for a 12C671 using MPLAB 3.40.  Trouble is I cannot =
> seem to get the I/O's to toggle under the simulator (no change in the =
> gpio SFR) by=20

Not sure what the simulator should be doing here but the hardware will
not work as you have programmed it.

>              movlw   b'00001001'        ;
>              movwf   TRISIO               ; port 0, 3 are inputs, rest =
> outputs

The 12C671 is almost certainly a 12bit core like the 12C508/9 which I have
used.  They do not use the TRISIO register as a regular register.

You have to use the TRIS instruction.  Best you examine the short
one page opcode listing to check which special opcodes are supported
when changing between 12, 14 or 16 bit programming.

Cheers