HT47R20A-1 实时时钟（Real Time Clock）使用介绍

程序清单：

include ht47r20a-1.inc

data .section 'data'

count db ?

code .section at 0 'code'

org 00h

jmp start

org 04h

reti

org 08h

reti

org 0ch ；实时时钟中断入口地址

jmp rtc_int

org 10h

reti

；-------------------------------------------

start:

clr intc0

clr intc1

mov a,77h

mov count,a

mov a,07h ；设定实时时钟超时周期

mov rtcc,a

set intc0.3 ；实时时钟中断允许

set intc0.0 ；总中断允许

jmp $ ；原地踏步，等待实时时钟中断

；-------------------------------------------

rtc_int: ；实时时钟中断服务子程序

rl count

mov a,count

mov pa,a ；输出到PA 口，点亮LED

reti