《微机原理与接口技术》课程设计Word格式.docx

1、8253的主要工作原理是：8253其本质为减一计数器，其工作过程为：首先需要设置工作方式，然后将工作方式处置置入计数初值锁存器；启动计数后，CPU向8253的计数初值锁存器赋初值，每来一个CLK信号，减一计数器减1，直到减到0或1时，就发出输出信号OUT输出74LS393（1）74LS393为一个双4位二进制计数器，主要用于二进制计数。（2）1CPVCC1RD2CP1QA2RD1QB2QA1QC2QB1QD2QCGND2QD4.工作原理示意图8253的CLK1接分频输出端1MHz。GATE1接PB0。OUT1接VIN（音频功放单元JP5V（ON）。CS30040H。JX8JX0。（6）IORD

2、IORD IOWRIOWR （7）A0A0 A1 A1（8）按1、27键，依次发出1、27音调声。5.程序设计流程图 6.程序代码CODE SEGMENTASSUME CS:CODE,DS:CODECONTROL equ 43hCOUNT0 equ 40hCOUNT1 equ 41hCOUNT2 equ 42h ；以上是定义8253地址端口IOCONPT EQU 0FF2BHIOBPT EQU 0FF29HIOAPT EQU 0FF28H ；以上定义8255端口地址PA EQU 0FF21H ;字位口PB EQU 0FF22H ;字形口PC EQU 0FF23H ;键入口 ；以上定义8155端

3、口地址 ORG 1000HSTART: JMP START0BUF DB KZltime db lkeydb ZP DW data1: db 0c0h,0f9h,0a4h,0b0h,99h,92h,82h,0f8h,80h,90h,88h,83h,0c6h,0a1h db 86h,8eh,0ffh,0ch,89h,0deh,0c7h,8ch,0f3h,0bfh,8FH,0F1Hdata3: dw 2273, 2024, 1805, 1704 dw 1517, 1353, 1205, 1136START0: mov ax,cs mov ds,ax CALL BUF1 MOV AL,88H MOV

4、 DX,IOCONPT OUT DX,AL mov dx,IOBPT mov al,00 out dx,al mov zp,offset bufredikey: call dispkey cmp KZ,09h JNC redikey cmp kz,01h jc redikey mov bx,zp mov al,kz mov bx,al cmp bx,offset buf+5 jz zp1 inc bx mov zp,bx jmp outtonezp1:outtone: mov al,0ffh mov ah,00h dec ax shl ax,1 mov bx,offset data3 add

5、bx,ax mov ax,bx call t8253 mov cx,20hcon1: push cx call disp pop cx loop con1 jmp redikeyt8253: push ax mov al, 76h ; 计数器1, 16位二进制,方式3。 mov dx, CONTROL out dx, al pop ax mov dx, COUNT1 mov al, ah ret;- dispkey: call key mov ah,al ;newkey mov bl,ltime ;ltime mov bh,lkey ;lkey mov al,01h mov dx,0ff21h

6、 cmp ah,bh mov bh,ah ;bh=new key mov ah,bl ;al=time jz disk4 mov bl,88h mov ah,88hdisk4: dec ah cmp ah,82h jz disk6 cmp ah,0eh cmp ah,00h jz disk5 mov ah,20h dec bl jmp disk7disk5: mov ah,0fhdisk6: mov bl,ah mov ah,bhdisk7: mov ltime,bl mov lkey,bh mov KZ,bh mov al,ahkey: mov dx,0ff22h mov bl,00h mo

7、v ah,0feh mov cx,08hkey1: rol al,01h mov ah,al nop mov dx,0ff23h in al,dx not al and al,0fh jnz key2 inc bl loop key1 jmp nkeYkey2: test al,01h je key3 mov al,00h jmp key6key3: test al,02h je key4 mov al,08hkey4: test al,04h je key5 mov al,10hkey5: test al,08h je nkey mov al,18hkey6: add al,bl cmp a

8、l,10h jnc fkey mov bl,al mov bh,0h mov si,offset data2 mov al,bx+sinkey: mov al,20hfkey:data2: db 07h,04h,08h,05h,09h,06h,0ah,0bh DB 01h,00h,02h,0fh,03h,0eh,0ch,0dhDISP: MOV AL,0FFH ;00H MOV DX,PA MOV CL,0DFH ;20H ;显示子程序 ,5ms MOV BX,OFFSET BUFDIS1: MOV AL,BX MOV AH,00H PUSH BX MOV BX,OFFSET DATA1 ADD BX,AX POP BX MOV DX,PB MOV AL,CL PUSH CXDIS2: MOV CX,0a0H LOOP $ POP CX CMP CL,0FEH JZ LX1 INC BX ROR CL,1 JMP DIS1LX1: MOV AL,0FFH RETBUF1: MOV BUF,11H MOV BUF+1,10H MOV BUF+2,10H MOV BUF+3,10H MOV BUF+4,10H MOV BUF+5,10H ENDS END START