You will need a pair of lines in the startup

Movlw		07h		; Val for all digital
Movwf		CMCON		; for the CMCON reg

Rgds Steve

-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
Jan van Dijk
Sent: 05 April 2007 14:36
To: Microcontroller discussion list - Public.
Subject: Re: [PIC] Converting 16F84 DCC decoder to 16F628 (or 16F648)

Okay, I'm altering the original file so it will work again with the 16C84,
but with using the microchip include file...

I found a rather strange thing, all registers maps to the register which are
defined in the P16C84.INC, only 2 do not:

assembly file DECODER.ASM:
eecon1  equ     08
rd      equ    0
wr      equ    1
wren    equ    2
eecon2  equ     09

include file P16C84:
EECON1                       EQU     H'0088'
EECON2                       EQU     H'0089'

These addresses are actually used, which rather surpises me, since they
don't match with the include file:

;Generic EE write subroutine that writes eedata into eeadr. If the processor
;is busy with a previous write operation, the subroutine returns without
;writing. Inputs are eeadr and eeread.

EEwrite movlw   0x55
        movwf   eecon2
        movlw   0xAA
        movwf   eecon2
        bsf     eecon1,wr
eewrcon btfsc   eecon1,wr
        goto    eewrcon
        bcf     eecon1,wren
        bcf     status,rp0
        return

Is there anyone who might have a clue what's going on?

Best regards,

Jan


2007/4/5, Jan van Dijk <iwritecode@gmail.com>:
>
> Hello,
>
> Thanks for the given input! I made a MPLAB project and added the assembler
> file to it. The code compiles when renaming the config to con_fig, but no
> include files are used...
>
> The control registers are defined in the program start:
>
> *;Variable definition - PIC16C84 control registers.*
>
> *f0      equ     00
> rtcc    equ     01
> pc      equ     02
> status  equ     03
> carry   equ    0
> zbit    equ    2
> rp0     equ    5
> rp1     equ    6
> fsr     equ     04
> porta   equ     05
> portb   equ     06
> eedata  equ     08
> eeadr   equ     09
> eecon1  equ     08
> rd      equ    0
> wr      equ    1
> wren    equ    2
> eecon2  equ     09
> pclath  equ     0A
> intcon  equ     0B
> f       equ    1
> w       equ *    0
>
> And they are used in the program... also some 'magical' numbers are used
> within the code to set the registers:
>
> *;Init sets porta as all outputs, pin b0 as input and the rest of portb as
> ;outputs and sets the rtcc counter to divide by 32 (16us at 8MHz clock).
> ;FSR is set to 88h for indirect access to INTCON register from page 00. *
>
> *Init    movlw   b'00000001'     ;RA0=input, RA1,2=outputs
>         tris    porta
>         clrf    porta
>         movlw   0x00            ;All of PortB = outputs
>         tris    portb
>         clrf    portb
>         clrf    intcon
>         movlw   0x84
>         option
>         movlw   0x88
>         movwf   fsr*
>
> Luckily the code is well documented... but I might have to do some
> puzzling then :)
>
> Best regards,
>
> Jan
>
>
>
> 2007/4/2, Herbert Graf <mailinglist3@farcite.net>:
> >
> > On Mon, 2007-04-02 at 21:11 +0100, Steve Smith wrote:
> > > Well if you replace all the labels 'config' with con_fig it compiles
> > for a
> > > 628 in mp lab but I haven't looked at the functional differences
> > between the
> > > parts shouldn't be too bad
> >
> > Hello Steve,
> >
> > There are a few issues you must look in to.
> >
> > First off, yes, you have to "translate" the config settings to the 628.
> > Generally the 628 has "more" stuff in the config section, so you must
> > turn off the things that the 16F84 doesn't have that may interfere with
> > operation.
> >
> > Second, the analog comparators in the 628 have to be turned off, by
> > default they are on.
> >
> > Third, and this is the one that either is zero work or TONS of work: you
> > have to look at how the assembly is written. If the writers used the
> > MChip include files, and did proper work with the bank settings ( i.e.
> > using BANKSEL) you should be OK. However, if they defined their own
> > symbols for FSRs, or, even worse, used the numeric values you have ALOT
> > of work ahead of you.
> >
> > Same with general RAM, if they did things proper you should be fine, if
> > they used "defines" with absolute numbers then you may have alot of work
> > ahead of you.
> >
> > Good luck!
> >
> > TTYL
> >
> > --
> > http://www.piclist.com PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
>
>
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