实验名称基于8255的LED显示函数信号发生器设计课题内容和要求基本要求Word下载.docx

实验名称基于8255的LED显示函数信号发生器设计课题内容和要求基本要求Word下载.docx

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SCAN:

MOVDPTR,#1FFCH;

PA口地址

MOVA,#00H

MOVX@DPTR,A;

PA0～PA3输出低电平

INCDPTR;

DPTR指向PC口

INCDPTR

MOVXA,@DPTR;

读PC口的值

ANLA,#0FH;

屏蔽无用位

CJNEA,#0FH,DETAIL;

判断是否有低电平

ACALLDELAY1;

延时

ACALLDELAY1

AJMPSCAN;

无键按下则继续扫描

DETAIL:

ACALLDELAY1;

消抖动

MOVDPTR,#1FFCH;

再判断是否有键按下

MOVX@DPTR,A

MOVXA,@DPTR

ANLA,#0FH

CJNEA,#0FH,CONTINUE;

有键按下则做进一步的判断

无键按下继续扫描

CONTINUE:

CLREA;

有键按下驱动蜂鸣器

SETBP1.7

ACALLDELAY2

CLRP1.7

SETBEA

MOVR4,#02H;

扫描行数送入R4中

MOVA,#0FEH

LINE:

MOVDPTR,#1FFCH

MOVR2,A;

行号送R2

置PA0为低电平

CJNEA,#0FH,FIND;

判断第一行是否有键按下

MOVA,R2

RLA

DJNZR4,LINE

SJMPSCAN;

FIND:

MOVR3,A列号存入R3中

CJNEA,#0FEH,LINE2;

判断是否是第一行有键按下

LINE1:

MOVA,R3;

第一行有键按下

CJNEA,#0EH,L1R2;

判断是哪个按键按下

L1R1:

MOVR0,#01H;

有波形键按下键按下

MOVR1,#01H;

波形标志1

MOVR7,#00H

CLRTR1

CLRTR0

SETBTR0

SJMPSCAN

L1R2:

CJNEA,#0DH,L1R3

MOVR0,#01H;

MOVR1,#02H;

方波标志

SETBTR1

L1R3:

MOVR1,#03H;

三角波标志

AJMPSCAN

LINE2:

第二行有键按下

CJNEA,#0EH,L2R2

L2R1:

CJNER0,#01H,NONE1;

有波形时才能进行频率增减操作

CJNER6,#00H,START1;

没有减到最小频率值时继续减否则减频操作失败

AJMPNONE1

START1:

DECR6;

减频

MOVA,R6

MOVDPTR,#TABLE3

MOVCA,@A+DPTR

MOVTH0,A;

重置计数初值

NONE1:

AJMPDISPLAY

L2R2:

CJNEA,#0DH,L2R3

CJNER0,#01H,NONE2;

CJNER6,#0EH,START2;

没有增到最大频率值时继续增否则增频操作失败

AJMPNONE2

START2:

INCR6;

增频

NONE2:

L2R3:

CJNEA,#0BH,L2R4;

显示波形周期值

MOVF,#01H

AJMPDISPLAY

L2R4:

MOVF,#00H;

显示波形频率值

2.显示部分

显示部分硬件图：

开发板上设置了6位8段数码管，采用动态扫描方式连接，各位数码管的A～DP互联后经拨码开关S1后由P0口控制，数码管的COM分别经拨码开关S2后由P10～P15控制。

当某一数码管COM口控制端为低电平时，三极管导通，该位数码管选中，此时可通过P0口发送待显示数据的编码。

显示部分流程图：

显示部分程序：

DISPLAY:

MOVA,F

CJNEA,#01H,FREQ;

判断F的值

AJMPTIME

FREQ:

CLREA;

显示频率值

MOVDPTR,#TAB1

MOVP1,#07EH

MOVP0,A

MOVDPTR,#TAB2

MOVP1,#07DH

MOVDPTR,#TAB3

MOVP1,#07BH

MOVDPTR,#TAB4

MOVP1,#077H

MOVA,T

DECA

MOVT,A

JNZDISPLAY

TIME:

显示周期值

MOVDPTR,#TAB5

MOVDPTR,#TAB6

MOVDPTR,#TAB7

MOVDPTR,#TAB8

3.波形产生部分

正弦波和三角波采用查表的方式来获得，每个完整周期有32个抽样值，采用T0中断方式将32个抽样值在所需的时间内显示出来。

方波采用算法输出，周期为T，采用T1中断没T/2中断一次输出高电平或低电平，每中断一次电平颠倒一次。

四、硬件电路图

五、源程序代码

KEQU30H;

存方波电平

TEQU32H;

显示扫描遍数

FEQU34H;

显示周期或频率标志

ORG0000H

AJMPMAIN

ORG000BH

LJMPTIME0

ORG001BH

LJMPTIME1

ORG0040H

MAIN:

MOVTMOD,#12H;

T0方式2，T1方式1

MOVTH0,#0FBH;

赋计数初值

MOVTL0,#0FBH

MOVTH1,#0FEH

MOVTL1,#2CH

MOVIE,#8AH;

CPU开中断，定时器中断开

MOVDPTR,#1FFFH;

写8255控制字

MOVA,#89H;

PA口输出，PC口输入

MOVR0,#00H

MOVR6,#09H

MOVT,#0FFH

MOVK,#0FFH

MOVF,#00H

MOVDPTR,#1FFFH

CJNEA,#89H,FZ

AJMPZC

FZ:

MOVA,#89H

ZC:

DELAY1:

MOVR4,#10;

延时子程序

AA1:

MOVR5,#250

AA:

DJNZR5,AA

DJNZR4,AA1

RET

DELAY2:

MOVR4,#30;

BB1:

BB:

DJNZR5,BB

DJNZR4,BB1

ORG0200H

TIME0:

PUSHACC;

2

PUSHDPH;

PUSHDPL;

MOVP1,#07FH;

1

CJNER1,#01H,KEY3;

KEY1:

MOVDPTR,#TABLE4;

MOVA,R7;

MOVCA,@A+DPTR;

MOVDPTR,#3FFFH;

INCR7;

AJMPRETURN;

KEY3:

MOVDPTR,#TABLE5;

RETURN:

POPDPL;

POPDPH;

POPACC;

RETI;

ORG0300H

TIME1:

MOVA,R6;

MOVDPTR,#TABLE1;

MOVTH1,A;

MOVDPTR,#TABLE2;

MOVTL1,A;

KEY2:

MOVA,K;

CPLA;

MOVK,A;

POPDPL;

TAB1:

DB0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H;

LED

DB0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H

TAB2:

DB0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H

TAB3:

DB0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H

DB98H,0C0H,0F9H,0A4H,0B0H,99H,92H

TAB4:

DB0C0H,0F9H,0F9H,0F9H,0F9H,0F9H,0F9H

TAB5:

DB0C0H,0C0H,0B0H,0C0H,0C0H,0F8H,0B0H,92H

DB0F9H,0C0H,0F9H,0B0H,0F8H,0F9H,0F8H

TAB6:

DB0C0H,0C0H,0B0H,92H,0C0H,82H,99H,0A4H

DB0F9H,0C0H,98H,80H,0F8H,0F8H,82H

TAB7:

DB40H,12H,30H,24H,24H,79H,79H,79H

DB79H,79H,40H,40H,40H,40H,40H

TAB8:

DB0F9H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H,0C0H

TABLE1:

DB0ECH,0F6H,0F9H,0FBH,0FCH,0FCH,0FDH,0FDH;

T1初值

DB0FDH,0FEH,0FEH,0FEH,0FEH,0FEH,0FEH

TABLE2:

DB9DH,61H,0A2H,43H,3CH,0E3H,5AH,0B4H

DB0E9H,31H,5EH,84H,0A4H,0BFH,0D7H

TABLE3:

DB00H,7EH,0B2H,0CCH,0DCH,0E6H,0EEH,0F3H;

T0初值

DB0F8H,0FBH,0FEH,0FFH,0FFH,0FFH,0FFH

TABLE4:

DB80H,98H,0B0H,0C7H,0DAH,0EAH,0F6H,0FDH;

sin

DB0FFH,0FDH,0F6H,0EAH,0DAH,0C7H,0B0H,98H

DB80H,67H,4FH,38H,25H,15H,09H,02H

DB00H,02H,09H,15H,25H,38H,4FH,67H

DB80H,98H,0B0H,0C7H,0DAH,0EAH,0F6H,0FDH;

DB80H,67H,4F