LED段码管的显示程序的编写

关于段码显示器的显示原理,其实就是将8个LED集成在一起组成一个8字型的器件,从而显示出我们想要的数字,现将编码表列出如下:

显示字符	共阴极段码	共阳极段码	显示字符	共阴极段码	共阳极段码
0	3FH	C0H	9	6FH	90H
1	06H	F9H	A	77H	88H
2	5BH	A4H	B	7CH	83H
3	4FH	B0H	C	39H	C6H
4	66H	99H	D	5EH	A1H
5	6DH	92H	E	79H	86H
6	7DH	82H	F	71H	8EH
7	07H	F8H	8.	FFH	00H
8	7FH	80H	灭	00H	FFH

在试验板上我用的是HCF4056或CD4056，这种LED驱动器好处就是能直接将数据显示出来，比如：我们要讲“6”显示出来，我们可将ABCD=6，再开通片璇即可，缺点是不能显示BCDEF,列表如下:

显示字符	ABCD		显示字符	ABCD
0	0		9	9
1	1		L	A
2	2		H	B
3	3		P	C
4	4		A	D
5	5		-	E
6	6		灭	F
7	7
8	8

 

下面我们来学习段码显示器的显示程序的编写方法.

    4.1.1点亮一个段码显示器   (程序编号为ONELED.ASM)

             试验板的原理图中, 我们下面讲的是直接I/O口操作,显示数据从P2口输出,让第一个显示器显示“6”，程序编写如下:

                 ORG      0000H

                     LJMP     START

                     ORG      0050H

START:

                     MOV     50H,#6

                     MOV     A,#0FFH                    ;关显示

                     MOV     P2,A

START1:

                     MOV     A,#0FH               ;清第1个显示器

                     ADD      A,#10H

                     MOV     P2,A

                     MOV     A,50H                  ;显示当前按键值     

                     ADD      A,#10H

                     MOV     P2,A     

                     LJMP     START1

DELAY:

                     PUSH    07H

                     PUSH    06H

                     MOV     R7,#08H

DELAY1:

                     MOV     R6,#200

                     DJNZ     R6,$

                     DJNZ     R7,DELAY1

                     POP       06H

                     POP       07H

                     RET

                     END

          上面的程序设计只是教我们如何去点亮一个段码显示器,在实际应用中这是毫无使用价值的,下面我们来讲试验板上的4位段码显示器全部显示为“6“.

4.1.2点亮4为段码显示器,让他们显示”6666”. (程序编号为: FOURLED.ASM)

     注: 今后如果没有特别说明,显存地址均为: 50----57H

             ORG      0000H

                     LJMP     START

                     ORG      0050H

START:

                     MOV     50H,#6

                     MOV     A,#0FFH                    ;请按键

                     MOV     P2,A

START1:

                     MOV     A,#0FH               ;清第1个显示器

                     ADD      A,#10H

                     MOV     P2,A

                     MOV     A,50H                  ;显示”6”             

                     ADD      A,#10H

                     MOV     P2,A     

                     MOV     A,#0FH               ;清第2个显示器

                     ADD      A,#20H

                     MOV     P2,A

                     MOV     A,50H                  ;显示”6”             

                     ADD      A,#20H

                     MOV     P2,A     

                     MOV     A,#0FH               ;清第3个显示器

                     ADD      A,#30H

                     MOV     P2,A

                     MOV     A,50H                  ;显示”6”             

                     ADD      A,#30H

                     MOV     P2,A     

                     MOV     A,#0FH               ;清第4个显示器

                     ADD      A,#40H

                     MOV     P2,A

                     MOV     A,50H                  ;显示”6”      

                     ADD      A,#40H

                     MOV     P2,A     

                     LJMP     START1

DELAY:

                     PUSH    07H

                     PUSH    06H

                     MOV     R7,#08H

DELAY1:

                     MOV     R6,#200

                     DJNZ     R6,$

                     DJNZ     R7,DELAY1

                     POP       06H

                     POP       07H

                     RET

                     END