Dutor

 	org 	8000h		;定位
	ljmp 	start
	org 	8100h
start:
	mov 	sp, #60h
	mov	tmod, #10h	;置T1为方式1
;	mov	tl1, #010h
;	mov	th1, #010h	;设初值，定时为50ms
	setb	tr1		;启动定时器T1
 
loop1:	
	mov	p1, #0ffh
	mov	a, p1
	mov	r5, a
	cpl 	a
	jz	loop1
	cjne	a, #01h, loop2
	sjmp	do
loop2:
	cjne	a, #02h, loop3
	sjmp	ra
loop3:
	cjne	a, #04h, loop4
	sjmp	mi
loop4:
	cjne	a, #08h, loop5
	sjmp	fa
loop5:
	cjne	a, #10h, loop6
	sjmp	so
loop6:
	cjne	a, #20h, loop7
	sjmp	la
loop7:
	cjne	a, #40h, loop8
	sjmp	xi
loop8:
	cjne	a, #80h, loop1
	sjmp	hdo
	sjmp	loop1
 
do:
	mov	r7, #0f9h
	mov	r6, #21h
	sjmp	loop
ra:
	mov	r7, #0f9h
	mov	r6, #0e0h
	sjmp	loop
mi:
	mov	r7, #0fah
	mov	r6, #08bh
	sjmp	loop
fa:
	mov	r7, #0fah
	mov	r6, #0d7h
	sjmp	loop
so:
	mov	r7, #0fbh
	mov	r6, #67h
	sjmp	loop
la:
	mov	r7, #0fbh
	mov	r6, #0e8h
	sjmp	loop
xi:
	mov	r7, #0fch
	mov	r6, #5bh
	sjmp	loop
hdo:
	mov	r7, #0fch
	mov	r6, #8eh
	sjmp	loop
 
loop:
	lcall 	music
	sjmp	loop1
music:
	mov	tl1, r6
	mov	th1, r7
 
loop9:
	jnb	tf1, $
	clr	tf1
	mov	tl1, r6
	mov	th1, r7
	cpl	p3.3
	mov	a, p1
	cpl	a
	jnz	loop9
	setb	p3.3
down:
	ret
	END