INCLUE for continuous clock

[Woodzy]

Hi all,
I have been using this little include on PIC16F876A's for ages without a flaw.
But, for some reason it wont work in an 877A.
Any tips or clues would be much appreciated.

cheers
Woodzy

========================================

'FILENAME : INT.BAS
'PROGRAM : INCLUE for continuous clock
'DATE : 01NOV2005

DEFINE INTHAND ROLLOVER

wsave var BYTE $020 SYSTEM
wsave1 var BYTE $0a0 SYSTEM
wsave2 var BYTE $120 SYSTEM
wsave3 var BYTE $1a0 SYSTEM
ssave var BYTE BANK0 SYSTEM
psave var BYTE BANK0 SYSTEM
i_hour var BYTE
i_minu var BYTE
i_sec var BYTE
i_tic var BYTE


GOTO AFTERINT 'Jump past interrupthandler

asm

ROLLOVER

;************************************************* ****************************************
;************************************************* ****************************************
;
; If you are using a PIC with 2K or less,
; you MUST unremarke the lines that follow.
;
; movwf wsave ;only for PICs with 2k or less
; swapf STATUS,w ;only for PICs with 2k or less
; clrf STATUS ;only for PICs with 2k or less
; movwf ssave ;only for PICs with 2k or less
; movf PCLATH,w ;only for PICs with 2k or less
; movwf psave ;only for PICs with 2k or less
;
;************************************************* ****************************************
;************************************************* ****************************************

; interrupcode follows here


movlw 0x58
movwf TMR1L
movlw 0x9e ;restart timer from ffff - 9e58 => 5Hz if using 4MHz
movwf TMR1H
decfsz _i_tic,f
goto slutint
incf _i_sec,f
movlw 5 ;5 = 1Hz if using 4MHz (change to 10 for 8MHz and so on)
movwf _i_tic

movf _i_sec,w
sublw 60
btfss STATUS,Z ;check for 60 sec
goto slutint ;no
clrf _i_sec ;yes
incf _i_minu,f

movf _i_minu,w
sublw 60
btfss STATUS,Z ;check for 60 minutes
goto slutint ;no
clrf _i_minu ;yes
incf _i_hour

movf _i_hour,w
sublw 24
btfss STATUS,Z ;check for 24 hours
goto slutint ;no
clrf _i_hour ;yes

slutint
bcf PIR1,0 ;zero tmr1 interrupt flag


;end of interruptcode
; restorecode follows here

movf psave,w ;restore
movwf PCLATH
swapf ssave,w
movwf STATUS
swapf wsave,f
swapf wsave,w
retfie

endasm


AFTERINT:

INTCON = %00000000 'all interrupts off
PIR1 = %00000000 'zero tmr1 interrupt flag
PIE1 = %00000001 'enable timer1 interrupt
TMR1L = $58
TMR1H = $9e
i_hour = 0
i_minu = 0
i_sec = 0
i_tic = 5 'this value should be the same as the value of line 8 in the ISR
T1CON = %00110001 'timer1 on, prescaler=1/8
INTCON = %11000000 'interrupt on

'-----------------------------------------------------------------------------------------

================================================

[Darrel Taylor]

The ASM routine assumes that the time variables are in BANK0.

If the program has grown in size, there may be more variables which push i_hour, i_minu, i_sec and i_tic into a different Bank.

Adding BANK0 modifiers to the variable declarations may help, but it's a long shot without knowing the rest of the code.
If the variables are still in BANK0, I see no reason why it shouldn't work with a 16F877A.

i_hour var BYTE BANK0
i_minu var BYTE BANK0
i_sec  var BYTE BANK0
i_tic  var BYTE BANK0

[Woodzy]

Darrel,
Thanks mate for your quick reply.
I will give your suggestion a go and get back to you.
cheers
Woodzy

[Woodzy]

Darrel,
Thankyou sir,
your advice worked a treat. ticking away happily now.
cherss
Woodzy