微機(jī)原理與接口技術(shù)-8254電子發(fā)聲器_課程設(shè)計_BY.doc

一 實驗名稱：發(fā)聲器二 功能及使用方法：設(shè)計一個電子琴發(fā)聲程序,并在運(yùn)行時通過實驗箱上的揚(yáng)聲器發(fā)聲,并且當(dāng)按下數(shù)字114時,依次發(fā)出1,2,3,4,5,6,7的低音和1，2，3，4，5，6，7的中音。并在實驗箱上的發(fā)聲器上發(fā)聲，這肯定需要有發(fā)聲程序,驅(qū)動發(fā)聲程序,還有鍵盤掃描程序,及為了能夠聽見清脆的字符音還得對程序進(jìn)行必要的延時。利用8254芯片所提供轉(zhuǎn)化后的頻率送到發(fā)聲單元進(jìn)行發(fā)聲及8255芯片送提供的輸入輸出功能，來完成從鍵盤的輸入到發(fā)聲裝置發(fā)聲的控制。電子發(fā)聲原理：一個音符對應(yīng)一個頻率，將對應(yīng)一個音符頻率的方波通到揚(yáng)聲器上，就可以發(fā)出這個音符的聲音。將一段樂曲的音符對應(yīng)頻率的方波一次送到揚(yáng)聲器，就可以演奏出這段樂曲。利用8254的“方波發(fā)生器”，將相應(yīng)的一種頻率的計數(shù)初值寫入計數(shù)器，就可以產(chǎn)生對應(yīng)頻率的方波。計數(shù)初值的計算如下：計數(shù)初值 = 輸入時鐘輸出頻率例如輸入時鐘采用1MHZ，要得到800HZ的頻率，計數(shù)初值即為1000000/800。音符與表的對照關(guān)系如上表所示。對于每一個音符的演奏時間，可以通過軟件延時來處理。首先確定單位延時子程序（根據(jù)CPU的頻率不同而有所變化）。然后確定每個音符演奏需要幾個單位延時，將此值送入寄存器，再調(diào)用延時子程序即可。三實驗器件：通過實驗箱上的揚(yáng)聲器發(fā)聲,并且當(dāng)按下數(shù)字114時,依次發(fā)出1,2,3,4,5,6,7的低音和1，2，3，4，5，6，7的中音。并在實驗箱上的發(fā)聲器上發(fā)聲。選用器件：8254和8255芯片各一片，微機(jī)一臺，TPC-H通用微機(jī)接口實驗系統(tǒng)一臺，揚(yáng)聲器和導(dǎo)線若干四電路連接圖：8254部分接線圖8255部分接線圖五各子程序功能1.為8255和8254所定義的端口地址：I0Y0 EQU 06C0HMY8254_COUNT0 EQU I0Y0+00HMY8254_COUNT1 EQU I0Y0+02HMY8254_COUNT2 EQU I0Y0+04HMY8254_MODE EQU I0Y0+06HMY8255_A EQU 0640HMY8255_B EQU 0642HMY8255_C EQU 0644HMY8255_MODE EQU 0646H2.頻率表及所對應(yīng)的時間表：FREQ_LIST DW 262H,294H,330H,349H,392H,440H,496H DW 523H,587H,659H,698H,784H,880H,988H DTABLE DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H DB 7FH,6FH,77H,7CH,39H,5EH,79H,71H3.定義8255和8254的控制字 MOV DX,MY8255_MODE MOV AL,81H OUT DX,AL MOV DX,MY8254_MODE MOV AL,36H OUT DX,AL4.CCSCAN子程序?qū)崿F(xiàn)取出按鍵值并輸入A口（清屏子程序）CCSCAN:MOV AL,00H MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_CIN AL,DXNOT ALAND AL,0FHRET5.Play輸出發(fā)音的子程序PLAY PROC MOV AH,0 MOV SI,AX SHL SI,1 MOV DX,0FH MOV AX,4240HDIV WORD PTR SIMOV DX,MY8254_COUNT0OUTDX,AL MOV AL,AH OUTDX,AL RETPLAY ENDP 6.延時子程序DALLY PROC D0: MOV CX,0010H D1: MOV AX,02H D2: DEC AX JNZ D2 LOOP D1 DEC DL JNZ D0RET DALLY ENDP 7.按鍵掃描功能COLUM: MOV AL,CH MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_C IN AL,DXL1:TEST AL,01HJNZ L2MOV AL,00HJMP KCODEL2:TEST AL,02HJNZ L3MOV AL,04HJMP KCODE L3:TEST AL,04HJNZ L4MOV AL,08HJMP KCODEL4:TEST AL,08HJNZ NEXTMOV AL,0CHKCODE: ADD AL,CL CALL PLAY PUSH AXKON:CALL DALLYCALL CCSCANJNZ KONPOP AXJMP BEGIN1六源程序清單I0Y0 EQU 06C0HMY8254_COUNT0 EQU I0Y0+00HMY8254_COUNT1 EQU I0Y0+02HMY8254_COUNT2 EQU I0Y0+04HMY8254_MODE EQU I0Y0+06HMY8255_A EQU 0640HMY8255_B EQU 0642HMY8255_C EQU 0644HMY8255_MODE EQU 0646HSTACK1 SEGMENT STACKDW 256 DUP(?)STACK1 ENDSDATA SEGMENTFREQ_LIST DW 262H,294H,330H,349H,392H,440H,496H DW 523H,587H,659H,698H,784H,880H,988H DTABLE DB 3FH,06H,5BH,4FH,66H,6DH,7DH,07H DB 7FH,6FH,77H,7CH,39H,5EH,79H,71HDATA ENDSCODE SEGMENTASSUME CS:CODE,DS:DATASTART:MOV AX,DATA MOV DS,AX MOV DX,MY8255_MODE MOV AL,81H OUT DX,AL MOV DX,MY8254_MODE MOV AL,36H OUT DX,ALBEGIN1: CALL CCSCAN JNZ INK1 JMP BEGIN1INK1: CALL CCSCAN JNZ INK2 JMP BEGIN1INK2:MOV CH,0FEH MOV CL,00HCOLUM: MOV AL,CH MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_C IN AL,DXL1:TEST AL,01HJNZ L2MOV AL,00HJMP KCODEL2:TEST AL,02HJNZ L3MOV AL,04HJMP KCODE L3:TEST AL,04HJNZ L4MOV AL,08HJMP KCODEL4:TEST AL,08HJNZ NEXTMOV AL,0CHKCODE: ADD AL,CL CALL PLAY PUSH AXKON:CALL DALLYCALL CCSCANJNZ KONPOP AXJMP BEGIN1NEXT:INC CL MOV AL,CHTEST AL,08HJZ KERRROL AL,1MOV CH,ALJMP COLUMKERR:JMP BEGIN1CCSCAN:MOV AL,00H MOV DX,MY8255_A OUT DX,AL MOV DX,MY8255_CIN AL,DXNOT ALAND AL,0FHRETPLAY PROC MOV AH,0 MOV SI,AX SHL SI,1 MOV DX,0FH MOV AX,4240HDIV WORD PTR SIMOV DX,MY8254_COUNT0