siren - copy.asm

我学单片机89C51时编的大部分程序都在里面

        ORG   0000H
        AJMP  START
        ORG 0030H
START:  MOV TMOD,#10H
        MOV R2,#02H
        MOV R3,#83H
        MOV R4,#08H
        MOV R5,#83H
        SETB  TR1
LOOP1:  MOV TH1,#0F8H     ;262Hz
        MOV TL1,#8CH
        JNB  TF1,$
        CLR  TF1
        CPL  P1.0
        DJNZ  R2,LOOP1
        MOV   R2,#02H
        DJNZ  R3,LOOP1
        MOV R3,#83H

LOOP2:  MOV TH1,#0FFH     ;1048Hz
        MOV TL1,#23H
        JNB  TF1,$
        CLR  TF1
        CPL  P1.0
        DJNZ  R4,LOOP2
        MOV   R4,#08H
        DJNZ  R5,LOOP2
        MOV R5,#83H
        LJMP  LOOP1