16f877a: PCLATH register

[Acetronics2]

Hi, Hervé

Here an example ( ASM source ... )

REDCYL ;SUB pour lire SEUIL et NCYL
movlw 1 ;Aller dans LTABLE chercher le SEUIL (negatif)
;de ligne rouge
bcf PCLATH,0 ;LTABLE est la page 2(en h200)
bsf PCLATH,1 ;donc PCLATH =2
call LTABLE

and somewhere further

LTABLE org h'200' ;Table des delais N =367 - 1500 t/mn(0° avant,soit T/4)
addwf PCL,f ;sauter au bon endroit h34=opcode pour RETLW

INCLUDE c:\aepl\Oltab.txt ;ici la LTABLE préalablement générée par le prog. gentab.bas


The goal is to retrieve a value in a Lookup table ...

BUT you NEED to know the page number ... where you want to jump to !!!

So, a solution is to place " manually" your called stubb to a known location ( not "squatted" ) by PbP ... :

ORG xxxx

CalledStubb
.....
.....

PbP example

'************************************************* ****************************
'Table des Valeurs d'avance en 200h - longueur Maxi 254 lignes !!!
'************************************************* ****************************

asm

bcf PCLATH,0
bsf PCLATH,1

call Table

Movwf _Avance

endasm

and further, at the very top high free program location.

asm


ORG 200h
Table

movfw _Index
addwf PCL,F

Include C:\Documents and Settings\Alain\Mes documents\Avance.txt


endasm

END

No secret there ...

Bonnes vacances ...

Alain

[herve]

Hi everybody,
Thank you for all your elements. I am waiting for the week-end to analyse them in details (lack of time during the week !).

Best regards,

Hervé.