doorbell.asm

来自「8951系列单片机仿真」· 汇编 代码 · 共 63 行

T5HZ		EQU 30H 
T7HZ		EQU 31H 
T05SA		EQU 32H 
T05SB		EQU 33H 
FLAG		BIT 00H 
STOP		BIT 01H 
SP1			BIT P3.7 
			ORG 00H 
			LJMP START 
			ORG 0BH 
			LJMP INT_T0 
START:		MOV TMOD,#02H 
			MOV TH0,#06H 
			MOV TL0,#06H 
			SETB ET0 
			SETB EA 
NSP:			JB SP1,NSP 
			LCALL DELY10MS 
			JB SP1,NSP 
			SETB TR0 
			MOV T5HZ,#00H 
			MOV T7HZ,#00H 
			MOV T05SA,#00H 
			MOV T05SB,#00H 
			CLR FLAG 
			CLR STOP		
			JNB STOP,$ 
			LJMP NSP 
DELY10MS:	MOV R6,#20 
D1:			MOV R7,#248 
			DJNZ R7,$ 
			DJNZ R6,D1 
			RET 
INT_T0:		INC T05SA 
			MOV A,T05SA 
			CJNE A,#100,NEXT 
			MOV T05SA,#00H 
			INC T05SB 
			MOV A,T05SB 
			CJNE A,#20,NEXT 
			MOV T05SB,#00H 
			JB FLAG,STP 
			CPL FLAG 
			LJMP NEXT 
STP:			SETB STOP 
			CLR TR0 
			LJMP DONE 
NEXT:		JB FLAG,S5HZ 
			INC T7HZ 
			MOV A,T7HZ 
			CJNE A,#03H,DONE 
			MOV T7HZ,#00H 
			CPL P1.0 
			LJMP DONE 
S5HZ:		INC T5HZ 
			MOV A,T5HZ 
			CJNE A,#04H,DONE 
			MOV T5HZ,#00H 
			CPL P1.0 
			LJMP DONE 
DONE:		RETI 
			END