USB 七段顯示器實驗

1 //8051 7S的程式碼範例
2
3 //規劃I/O埠A,B,C,D控制的相關暫存器記憶體位址
4 xdata char PORTACFG _at_ 0x7F93;
5 xdata char PORTBCFG _at_ 0x7F94;
6 xdata char PORTCCFG _at_ 0x7F95;
7 xdata char OUTA _at_ 0x7F96;
8 xdata char OUTB _at_ 0x7F97;
9 xdata char OUTC _at_ 0x7F98;
10 xdata char PINSA _at_ 0x7F99;
11 xdata char PINSB _at_ 0x7F9A;
12 xdata char PINSC _at_ 0x7F9B;
13 xdata char OEA _at_ 0x7F9C;
14 xdata char OEB _at_ 0x7F9D;
15 xdata char OEC _at_ 0x7F9E;
16 xdata char OUTD _at_ 0x7841;
17 xdata char PINSD _at_ 0x7842;
18 xdata char OED _at_ 0x7843;
19
20 #define DISPLAYTIME 500 // approx. milliseconds
21 unsigned char Da[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
22 void delay (int time)
23 {
24 1 int i,k;
25 1 for (k=0; k26 1 for (i=0; i<400; i++);
27 1 }
28 // 共陽極7-SEG解碼電路
29
30
31 void main()
32 {
33 1 unsigned char a=0;
34 1 PORTBCFG = 0x00;
35 1 OEB = 0xFF;
36 1 OED = 0xFF;
37 1
38 1 while(1)
39 1 {
40 2 for( a=0 ; a<=9 ; a++)
41 2 {
42 3
43 3 OUTD=Da[a];
44 3 OUTB=0x0e;
45 3 delay(DISPLAYTIME);
46 3
47 3 }
48 2
49 2 }
50 1 }