1．实验任务

在8X8点阵式LED显示“★”、“●”和心形图，通过按键来选择要显示的图形。

2．电路原理图

3．硬件系统连线

(1)．把“单片机系统”区域中的P1端口用8芯排芯连接到“点阵模块”区域中的“DR1－DR8”端口上；

(2)．把“单片机系统”区域中的P3端口用8芯排芯连接到“点阵模块”区域中的“DC1－DC8”端口上；

(3)．把“单片机系统”区域中的P2.0/A8端子用导线连接到“独立式键盘”区域中的SP1端子上；

4．程序设计内容

(1)．“★”在8X8LED点阵上显示图如下图所示

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1	2	3	4	5	6	7	8

12H，14H，3CH，48H，3CH，14H，12H，00H

(2)．“●”在8X8LED点阵上显示图如下图所示


			●	●	●
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1	2	3	4	5	6	7	8

00H，00H，38H，44H，44H，44H，38H，00H

(3)．心形图在8X8LED点阵上显示图如下图所示


	●	●		●	●
●			●			●
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		●		●
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1	2	3	4	5	6	7	8

30H，48H，44H，22H，44H，48H，30H，00H

5．汇编源程序

        CNTA EQU 30H
        COUNT EQU 31H
        ORG 00H
        LJMP START
        ORG 0BH
        LJMP T0X

        ORG 30H
START:  MOV CNTA,#00H
        MOV COUNT,#00H
        MOV TMOD,#01H
        MOV TH0,#(65536-4000) / 256
        MOV TL0,#(65536-4000) MOD 256
        SETB TR0
        SETB ET0
        SETB EA
WT:     JB P2.0,WT
        MOV R6,#5
        MOV R7,#248
D1:     DJNZ R7,$
        DJNZ R6,D1
        JB P2.0,WT
        INC COUNT
        MOV A,COUNT
        CJNE A,#03H,NEXT
        MOV COUNT,#00H
NEXT:   JNB P2.0,$
        SJMP WT

T0X:    NOP
        MOV TH0,#(65536-4000) / 256
        MOV TL0,#(65536-4000) MOD 256
        MOV DPTR,#TAB
        MOV A,CNTA
        MOVC A,@A+DPTR
        MOV P3,A
        MOV DPTR,#GRAPH
        MOV A,COUNT
        MOV B,#8
        MUL AB
        ADD A,CNTA
        MOVC A,@A+DPTR
        MOV P1,A
        INC CNTA
        MOV A,CNTA
        CJNE A,#8,NEX
        MOV CNTA,#00H
NEX:    RETI

TAB:    DB 0FEH,0FDH,0FBH,0F7H,0EFH,0DFH,0BFH,07FH
GRAPH:  DB 12H,14H,3CH,48H,3CH,14H,12H,00H
        DB 00H,00H,38H,44H,44H,44H,38H,00H
        DB 30H,48H,44H,22H,44H,48H,30H,00H
        END

6．C语言源程序

#include <AT89X51.H>
unsigned char code tab[] = {0xfe, 0xfd, 0xfb, 0xf7, 0xef, 0xdf, 0xbf, 0x7f};
unsigned char code graph[3][8] = {{0x12, 0x14, 0x3c, 0x48, 0x3c, 0x14, 0x12, 0x00},
    {0x00, 0x00, 0x38, 0x44, 0x44, 0x44, 0x38, 0x00},
    {0x30, 0x48, 0x44, 0x22, 0x44, 0x48, 0x30, 0x00}
};
unsigned char count;
unsigned char cnta;

void main(void)
{
    unsigned char i, j;
    TMOD = 0x01;
    TH0 = (65536 - 4000) / 256;
    TL0 = (65536 - 4000) % 6;
    TR0 = 1;
    ET0 = 1;
    EA = 1;
    while (1) {
        if (P2_0 == 0) {
            for (i = 5; i > 0; i--)
                for (j = 248; j > 0; j--);
            if (P2_0 == 0) {
                count++;
                if (count == 3) {
                    count = 0;
                }
                while (P2_0 == 0);
            }
        }
    }
}

void t0(void) interrupt 1 using 0
{
    TH0 = (65536 - 4000) / 256;
    TL0 = (65536 - 4000) % 6;
    P3 = tab[cnta];
    P1 = graph[count][cnta];
    cnta++;
    if (cnta == 8) {
        cnta = 0;
    }
}

可能会用到的工具/仪表

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