"Only Mother is Good in the World" 51 MCU Assembly Language Program

      ;2007-5-22     Author: Xu Xuejun
      ;Note that there is a 51 single-chip C language program corresponding to it
      ;This program has been debugged on the hardware
      ;The single-chip crystal oscillator of this program uses 11.0592MHz Z
SPK BIT P1.7
ORG 0000H
LJMP MAIN
ORG 000BH
LJMP TIMER0
MAIN:
MOV TMOD,#01H ;Set CT0 timing working mode 1
MOV IE,#82H     ;CPU opens interrupt, CT0 opens interrupt
       MOV R5,#0
PLAY:   
       MOV A,R5   
       MOV DPTR,#TABLE1
       MOVC A,@A+DPTR
       MOV     R6,A
       INC R5
       MOV A,R5
       MOVC A,@A+DPTR
       MOV     R7,A
        INC R5
       MOV A,R5
       MOVC A,@A+DPTR
       JNZ PLAY1
       MOV R5,#0
       LJMP PLAY
PLAY1:
       MOV B,#3
       MUL AB
       MOV R2,A
       MOV B,#7
       MOV A,R7
       MUL AB
       ADD A,R6
       DEC A
       MOV R6,A
       MOV DPTR,#FREQH
       MOVC A,@A+DPTR
       MOV R4,A
       MOV DPTR,#FREQL
       MOV A,R6
       MOVC A,@A+DPTR
       MOV R3,A
       LCALL SONG     ;Call the note player program
INC R5
SJMP PLAY     ;Move to the next note OV R3,A
  
SONG:
MOV TH0,R4
MOV TL0,R3
SETB TR0     ;Start CT0 (start singing a certain note)
DELAY:
MOV R1,#85H     ;Beat delay (how long a certain note is sung)
DEL1:
MOV R0,#0FFH
DEL0:
NOP
NOP
NOP
DJNZ R0,DEL0
DJNZ R1,DEL1
DJNZ R2,DELAY
CLR TR0     ; Disable CT0 (stop after a certain note is sung)
RET
TIMER0:       ; Timer interrupt program (used to determine how high a certain note is sung)
CPL SPK
MOV TH0,R4
MOV TL0,R3
RETI

     TABLE1:
      DB     6,2,3,     5,2,1,     3,2,2, 5,2,2, 1,3,2, 6,2,1, 5,2,1
      DB     6,2,4 ,     3,2,2,     5,2,1, 6,2,1, 5,2,2, 3,2,2, 1,2,1
      DB     6,1,1,     5,2,1,     3 ,2,1, 2,2,4, 2,2,3, 3,2,1, 5,2,2
      DB     5,2,1,     6,2,1,     3,2,2, 2,2 ,2, 1,2,4, 5,2,3, 3,2,1
      DB     2,2,1,     1,2,1,     6,1,1, 1,2,1, 5,1,6 , 0,0,0
    ; Scale frequency table
FREQH:
          DB        0F2H,0F3H,0F5H,0F5H,0F6H,0F7H,0F8H
          DB        0F9H,0F9H,0FAH,0FAH,0FBH,0FBH,0FCH, 0FCH;1,2,3,4,5,6,7, 8,i
          DB             0FCH,0FDH,0FDH,0FDH,0FDH,0FEH
          DB        0FEH,0FEH,0FEH,0FEH,0FEH,0FEH,0FFH
FREQL:
          DB        42H, 0C1H, 17H, 0B6H,0D0H,0D1H,0B6H
          DB        21H, 0E1H, 8CH, 0D8H,68H, 0E9H, 5BH,     8FH ;1,2,3,4,5,6,7,8,i
          DB             0EEH,44H,      6BH,0B4H,0F4H,2DH
          DB        47H, 77H,0A2H,0B6H,0DAH,0FAH,16H
          END