一个程序问题

2万 · 2011-1-18 21:12

MAIN:
            NOP
            NOP
            ADI F_TIMER,0001B
            BA0 HALTMODE ;未到5ms, 跳转
            ANDIM F_TIMER,1110B ;清"5ms 到"标志
            NOP
            LDA PORTD,00H
            STA TEMP,00H
            SBI TEMP,0FH;=0,没有按键动作跳走
            BAZ YS_4
            ADIM TEMP5,01H
            SBI TEMP5,01H;是否是第一次按键按下是的话存起来初次按键值
            BAZ YS_5
            LDA KEY_OLD,00H
            SUB TEMP,00H
            BNZ YS_4
            SBI TEMP5,03H;扫描8次按键未完成继续扫描
            BNZ MAIN
            ANDIM TEMP5,00H
            LDA T0M_1,00H;判断开机标志位
            BA0 YS_8
            LDA TEMP,00H
            BA0 YS_4
AS_1:
            ORIM T0M_1,01H;设置开机标志
            JMP MAIN
YS_8:
            LDA KEY_OLD,00H
            BA1 YS_4
            JMP YS_7
HALTMODE:
            NOP
            HALT
            NOP
            NOP
            JMP MAIN
YS_4:
            ANDIM F_TIMER,1110B
            ANDIM TEMP5,00H
            JMP MAIN
YS_5:
            LDA TEMP,00H
            STA KEY_OLD,00H
            RTNI
YS_7:
            LDI PORTC,0FH
            ADI F_TIMER,0010B
            BA1 YS_7
            ANDIM F_TIMER,1101B
            LDI PORTC,00H
            JMP
MAIN
            END