sound.asm

又一个语音LCD GAME

;============================================================================================
;============================================================================================
PlaySound:
;	JB	B_Demo,NoPlaySound
        STA     SoundPtr                ; "SoundPtr" * 3
        CLC                             ;
        ROL                             ;
        ADC     SoundPtr                ;
        STA     R_Index	                ; "Xi" is a dummy X register

	INC	R_Index
	
        LDA     #SOUND_START/100H
        STA	R_Index+1
        
        LDA     (R_Index)			; load the OffsetValue of the "SoundLen"  ("X")  
        					;R_TEMP
        CLC
        ADC	R_Index+1
        STA	Sound_Start
        
        DEC	R_Index
      	LDA	(R_Index)
        STA	R_Index
        
        LDA	Sound_Start
        STA	R_Index+1
        
	LDA	(R_Index)
	CLC
	ADC	#01H
        STA     SoundLen		; store the "length" of the sound file
        INC	R_Index			; 
        INC	R_Index
        LDA	(R_Index)
        STA	Speed			; store the "speed" for playing sound
        STA	SpeedCnt		; store down counter of the "speed"
        INC	R_Index
        INC	R_Index
        INC	R_Index
        LDA	R_Index
        STA	SoundPtr		; store the first byte of the SoundFile to "SoundPtr"
        
        SETB    fSounding
	TMR0_ON				; open tmr0
	PWM_ON
	
NoPlaySound:
        RTS

;--------------------------------
DivUpdateSound:
        JNB     fSounding,exSd		; if no fSounding, exit
        DEC     SpeedCnt
        BNE     exSd			; if SoundCnt<>0, sound continue
        LDA     Speed
        STA     SpeedCnt		; store the "Speed" to "SpeedCnt" for next "syllable"
        LDA     SoundLen
        BEQ     EndSound		; if "SoundLen"=0, sound end
        DEC     SoundLen
        
        LDA     SoundPtr
        STA	R_Index
        
        LDA     Sound_Start
   	STA	R_Index+1   
        
        LDA     (R_Index)			; load the syllable
        EOR     #0FFH
	CLC
	ADC	#01H
	BCS     ?silence		; if the "syllable"=0, sound switch off
        STA	TMR0  			; store to tmr0
        PWM_ON        			; sound switch on
        JMP     ?ext
?silence
        PWM_OFF       			; sound switch off
?ext
        INCW     SoundPtr		; "SoundPtr"+1, point to the next "syllable"
exSd:
        RTS
EndSound:
        CLRB    fSounding
        TMR0_OFF			; tmr0 close
        PWM_OFF   			; sound switch off
        RTS

;===================================================================================
F_UpDataSound:
	IF_NOT_DIV_IRQ_FLAG  F_UpDataSound
	CLR_DIV_IRQ_FLAG
	JSR	DivUpdateSound
	RTS
;=====================================================================