24C02计数器实战 计数器, 实战

fghser

1. ;24c02的开机计数器，系统复位或停送电一次数码管加1
   
2. ;***************************************************************************
   
3. ;* (程序转载请著明出处 ，www.wenqi89s51.com) *
   
4. 
   
5. SDA24 EQU P3.6
   
6. SCLK24 EQU P3.7
   
7. 
   
8. ORG 0000H
   
9. AJMP MAIN
   
10. ORG 0030H
    
11. MAIN:
    
12. 
    
13. MOV SP,#70H;设置堆栈栈顶
    
14. MOV DPTR,#TAB
    
15. MOV A,#00H ;读地址
    
16. LCALL RD24
    
17. CJNE A,#10,TT
    
18. TT: JNC TT1
    
19. AJMP TT2
    
20. TT1: MOV A,#00
    
21. TT2: MOV 30H,A
    
22. MOVC A,@A+DPTR
    
23. CLR P2.0 ;开数码管
    
24. MOV P0,A ;送显示
    
25. 
    
26. MOV A,30H
    
27. INC A
    
28. MOV B,A
    
29. MOV A,#00H
    
30. LCALL WT24
    
31. AJMP $
    
32. TAB: DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H;七段数码管0-9字形编码
    
33. 
    
34. 
    
35. RD24: PUSH ACC ;读24C02子程序。
    
36. SETB SDA24
    
37. CLR SCLK24
    
38. CALL START24
    
39. MOV A,#0A0H
    
40. CALL SHIFT8
    
41. CALL ACK
    
42. POP ACC
    
43. CALL SHIFT8
    
44. CALL ACK
    
45. CALL START24
    
46. MOV A,#0A1H
    
47. CALL SHIFT8
    
48. CALL ACK
    
49. SETB SDA24
    
50. MOV R7,#8
    
51. CLR A
    
52. SETB SDA24
    
53. RD000: RL A
    
54. SETB SCLK24
    
55. MOV C,SDA24
    
56. MOV ACC.0,C
    
57. CLR SCLK24
    
58. DJNZ R7,RD000
    
59. RET
    
60. ;-------------------------------
    
61. ;写入24C02程序：
    
62. WT24: PUSH ACC
    
63. SETB SDA24
    
64. CLR SCLK24
    
65. CALL START24
    
66. MOV A,#0A0H
    
67. CALL SHIFT8
    
68. CALL ACK
    
69. POP ACC
    
70. CALL SHIFT8
    
71. CALL ACK
    
72. MOV A,B
    
73. CALL SHIFT8
    
74. CALL ACK
    
75. CALL STOP
    
76. CALL DELAY2
    
77. RET
    
78. ; -------------------------------
    
79. ;开始条件
    
80. START24:CLR SDA24
    
81. SETB SDA24
    
82. SETB SCLK24
    
83. CLR SDA24
    
84. CLR SCLK24
    
85. RET
    
86. 
    
87. ;停止条件
    
88. STOP: CLR SDA24
    
89. SETB SCLK24
    
90. SETB SDA24
    
91. RET
    
92. 
    
93. ;应答信号
    
94. ACK: SETB SCLK24
    
95. CLR SCLK24
    
96. RET
    
97. 
    
98. ;读、写数据
    
99. SHIFT8: MOV R7,#8
    
100. SH01: RLC A
     
101. MOV SDA24,C
     
102. SETB SCLK24
     
103. CLR SCLK24
     
104. DJNZ R7,SH01
     
105. RET
     
106. 
     
107. DELAY2:
     
108. NOP
     
109. NOP
     
110. NOP
     
111. NOP
     
112. RET
     
113. END

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