952.asm

来自「单片机开发资料光盘-双龙-686M.zip」· 汇编 代码 · 共 32 行

.include "8535def.inc"
.org $0000
 rjmp main
.org $0006
 rjmp tim1_compa
main:    ldi r16,low(ramend)   ;栈指针置初值
         out spl,r16
         ldi r16,high(ramend)
         out sph,r16
         ldi r16,$01           ;PC0口定义为输出口
         out ddrc,r16          
         ldi r16,$10           ;允许T1比较匹配A中断
         out timsk,r16
         clr r16               ;置TCNT1初值为0
         out tcnt1l,r16
         out tcnt1h,r16
         ldi r16,$7a           ;ocr1a置$7a12,即1秒中断一次
         out ocr1ah,r16
         ldi r16,$12
         out ocr1al,r16
         ldi r16,$0c           ;T/C1对主频256分频定时
         out tccr1b,r16         
         sei
here:    rjmp here
tim1_compa:
        in r1,sreg             ;保护标志
        in r2,portc            ;PC口取反
        com r2
        out portc,r2        
        out sreg,r1            ;恢复标志
        reti