Holtek HT48R70A-1 - Page 60

include ht48r50a-1.inc
jmp begin
:
:
org 04h ; external interrupt vector
reti
org 08h ; timer-counter 0 interrupt vector
jmp tmr0int ; jump here when timer 0 overflows
org 0ch ; timer-counter 1 interrupt vector
jmp tmr1int ; jump here when timer 1 overflows
:
:
org 20h ; main program
:
:
;internal timer 0 interrupt routine
tmr0int:
:
;timer 0 main program placed here
:
reti
:
;internal timer 1 interrupt routine
tmr1int:
:
; timer 1 main program placed here
:
reti
:
:
begin:
;setup timer 0 registers
mov a,09bh ; setup timer 0 preload value
mov tmr0,a;
mov a,081h ; setup timer 0 control register
mov tmr0c,a ; timer mode and prescaler set to /4
;setup_timer 1 registers
clr tmr1l ; clear both low and high bytes to give maximum
; count
clr tmr1h
mov a,080h ; setup timer 1 control register
mov tmr1c,a ; timer 1 has no prescaler
;setup interrupt register
mov a,00dh ; enable master interrupt and both timer
; interrupts
mov intc,a
:
:
set tmr0c.4 ; start timer 0
set tmr1c.4 ; start timer 1
:
:
Chapter 1 Hardware Structure
51