music_hb.a51

利用蜂鸣器播放音乐. 这是刚学51单片机时制作的一个小程序

/*-------------------------------------------------------------------------------------------------
                      ╔=======================================╗
                      ┆       YG51A开发板配套实验学习例程   ┆
                      ┆             Version 2.0             ┆
                      ┆                                     ┆
                      ┆            扬光电子工作室           ┆
                      ┆                                     ┆
                      ┆           QQ:573764777              ┆
                      ┆         E-mail:[e-mail]       ┆
                      ╚=======================================╝
*********************************** 程序功能说明 *********************************************
演奏生日快乐歌
********************************************************************************************/
	org 0000h
	ajmp main
	org 000bh
	jmp tim0
	org 0030h
  main: ;主程序
	mov tmod,#01h ;设定时方式
	mov ie,#82h ;开中断
 start0:
	mov 30h,#00h ;
  next: mov a,30h
	mov dptr,#table
	movc a,@a+dptr ;查表取音调和节拍
	mov r2,a
	jz end0 ;为零,不进行处理.
	anl a,#0fh
	mov r5,a ;将节拍存入R5
	mov a,r2
	swap a
	anl a,#0fh
	jnz sing ;根据音调决定是否演奏.
	clr tr0
	jmp d1
  sing: dec a
	mov 22h,a ;将音调存入22H.
	rl a
	mov dptr,#table1
	movc a,@a+dptr ;根据音调决定定时器初值.
	mov th0,a ;放入TH0
	mov 21h,a
	mov a,22h
	rl a
	inc a
	movc a,@a+dptr
	mov tl0,a ;放入TL0
	mov 20h,a
	setb tr0 ;启动定时
    d1: call delay
	inc 30h
	jmp next
  end0: clr tr0
	jmp start0

tim0: ;定时器中断服务程序
	push acc
	push psw
	mov tl0,20h ;重赋初值.
	mov th0,21h
	cpl p2.4 
	pop psw
	pop acc
	reti

 delay: mov r7,#02h ;延时子程序
    d2: mov r4,#187
    d3: mov r3,#248
	djnz r3,$
	djnz r4,d3
	djnz r7,d2
	djnz r5,delay
	ret

table1: ;决定音调的定时初值.
    dw 64260,64400,64524,64580
    dw 64684,64777,64820,64898
    dw 64968,65030,65058,65110
    dw 65157,65178,65217

table: ;决定音调和节拍的表格,不同的歌曲只是此表不同
;1
db 82h,01h,81h,94h,84h,0b4h,0a4h,04h,82h,01h,81h,94h,84h,0c4h,0b4h,04h
;2
db 82h,01h,81h,0f4h,0d4h,0b4h,0a4h,94h,0e2h,01h,0e1h,0d4h,0b4h,0c4h,0b4h,04h
;3
db 82h,01h,81h,94h,84h,0b4h,0a4h,04h,82h,01h,81h,94h,84h,0c4h,0b4h,04h
;4
db 82h,01h,81h,0f4h,0d4h,0b4h,0a4h,94h,0e2h,01h,0e1h,0d4h,0b4h,0c4h,0b4h,04h,00
end