IIC总线程序代码

幽灵鸟

1. /*往24C02中写一个数据，然后读出来送到P1口上*/
   
2. #include<reg52.h>
   
3. #include <intrins.h>
   
4. #define uchar unsigned char
   
5. sbit sda=P0^1;
   
6. sbit scl=P0^0;
   
7. uchar a;
   
8. void delay()
   
9. {
   
10. uchar a;
    
11. for(a=1;a>0;a--);
    
12. }
    
13. void start() //开始信号
    
14. {
    
15. sda=1;
    
16. delay();
    
17. scl=1;
    
18. delay();
    
19. sda=0;
    
20. delay();
    
21. }
    
22. 
    
23. void stop()&#160;//停止
    
24. {
    
25. sda=0;
    
26. delay();
    
27. scl=1;
    
28. delay();
    
29. sda=1;
    
30. delay();
    
31. }
    
32. 
    
33. void respons() //应答
    
34. {
    
35. uchar i;
    
36. scl=1;
    
37. delay();
    
38. while((sda==1)&&(i<250))i++;
    
39. scl=0;
    
40. delay();
    
41. }
    
42. 
    
43. void init()
    
44. {
    
45. sda=1;
    
46. delay();
    
47. scl=1;
    
48. delay();
    
49. }
    
50. 
    
51. void write_byte(uchar date)
    
52. {
    
53. uchar i,temp;
    
54. temp=date;
    
55. 
    
56. 
    
57. for(i=0;i<8;i++)
    
58. {
    
59. temp=temp<<1;
    
60. scl=0;
    
61. delay();
    
62. sda=CY;
    
63. delay();
    
64. scl=1;
    
65. delay();
    
66. 
    
67. }
    
68. scl=0;
    
69. delay();
    
70. sda=1;
    
71. delay();
    
72. }
    
73. 
    
74. uchar read_byte()
    
75. {
    
76. uchar i,k;
    
77. scl=0;
    
78. delay();
    
79. sda=1;
    
80. delay();
    
81. for(i=0;i<8;i++)
    
82. {
    
83. scl=1;
    
84. delay();
    
85. k=(k<<1)|sda;
    
86. scl=0;
    
87. delay();
    
88. }
    
89. return k;
    
90. }
    
91. 
    
92. void delay1(uchar x)
    
93. {
    
94. uchar a,b;
    
95. for(a=x;a>0;a--)
    
96. for(b=100;b>0;b--);
    
97. }
    
98. 
    
99. void write_add(uchar address,uchar date)
    
100. {
     
101. start();
     
102. write_byte(0xa0);
     
103. respons();
     
104. write_byte(address);
     
105. respons();
     
106. write_byte(date);
     
107. respons();
     
108. stop();
     
109. }
     
110. 
     
111. uchar read_add(uchar address)
     
112. {
     
113. uchar date;
     
114. start();
     
115. write_byte(0xa0);
     
116. respons();
     
117. write_byte(address);
     
118. respons();
     
119. start();
     
120. write_byte(0xa1);
     
121. respons();
     
122. date=read_byte();
     
123. stop();
     
124. return date;
     
125. }
     
126. 
     
127. void main()
     
128. {
     
129. init();
     
130. write_add(23,0x55);
     
131. delay1(100);
     
132. P1=read_add(23);
     
133. while(1);
     
134. }
     

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cusnoopy

有意思。。。