不同入口，不同调用


interrupt 8
{
    if (S2CON & S2RI)
    {
        S2CON &= ~S2RI;     //Clear receive interrupt flag
        P0 = S2BUF;         //P0 show UART data
        P2 = (S2CON & S2RB8);//P2.2 show parity bit
    }
    if (S2CON & S2TI)
    {
        S2CON &= ~S2TI;     //Clear transmit interrupt flag
        busy = 0;           //Clear transmit busy flag
    }
}

沙发的程序可以一试

楼上说得对,串口2 中断 要使用  interrupt 8.
--------------
从你给的图看,串口1 中断 和 串口2 中断 都使用 interrupt 4, 这个肯定有问题.
建议: 把串口2 中断 改为  interrupt 8.

STC12C5A60S2单片机 串口2 中断 要使用  interrupt 8

1. /*------------------------------------------------------------------*/
   
2. /* --- STC MCU Limited ---------------------------------------------*/
   
3. /* --- STC12C5Axx Series MCU UART2 (8-bit/9-bit)Demo ---------------*/
   
4. /* --- Mobile: (86)13922805190 -------------------------------------*/
   
5. /* --- Fax: 86-0513-55012956,55012947,55012969 ---------------------*/
   
6. /* --- Tel: 86-0513-55012928,55012929,55012966----------------------*/
   
7. /* If you want to use the program or the program referenced in the  */
   
8. /* article, please specify in which data and procedures from STC    */
   
9. /*------------------------------------------------------------------*/
   
10. 
    
11. #include "reg51.h"
    
12. #include "intrins.h"
    
13. 
    
14. typedef unsigned char BYTE;
    
15. typedef unsigned int WORD;
    
16. 
    
17. #define FOSC 11059200L      //System frequency
    
18. #define BAUD 115200         //UART baudrate
    
19. 
    
20. /*Define UART parity mode*/
    
21. #define NONE_PARITY     0   //None parity
    
22. #define ODD_PARITY      1   //Odd parity
    
23. #define EVEN_PARITY     2   //Even parity
    
24. #define MARK_PARITY     3   //Mark parity
    
25. #define SPACE_PARITY    4   //Space parity
    
26. 
    
27. #define PARITYBIT EVEN_PARITY   //Testing even parity
    
28. 
    
29. /*Declare SFR associated with the UART2 */
    
30. sfr AUXR  = 0x8e;           //Auxiliary register
    
31. sfr S2CON = 0x9a;           //UART2 control register
    
32. sfr S2BUF = 0x9b;           //UART2 data buffer
    
33. sfr BRT   = 0x9c;           //Baudrate generator
    
34. sfr IE2   = 0xaf;           //Interrupt control 2
    
35. 
    
36. #define S2RI  0x01          //S2CON.0
    
37. #define S2TI  0x02          //S2CON.1
    
38. #define S2RB8 0x04          //S2CON.2
    
39. #define S2TB8 0x08          //S2CON.3
    
40. 
    
41. bit busy;
    
42. 
    
43. void SendData(BYTE dat);
    
44. void SendString(char *s);
    
45. 
    
46. void main()
    
47. {
    
48. #if (PARITYBIT == NONE_PARITY)
    
49.     S2CON = 0x50;           //8-bit variable UART
    
50. #elif (PARITYBIT == ODD_PARITY) || (PARITYBIT == EVEN_PARITY) || (PARITYBIT == MARK_PARITY)
    
51.     S2CON = 0xda;           //9-bit variable UART, parity bit initial to 1
    
52. #elif (PARITYBIT == SPACE_PARITY)
    
53.     S2CON = 0xd2;           //9-bit variable UART, parity bit initial to 0
    
54. #endif
    
55. 
    
56.     BRT = -(FOSC/32/BAUD);  //Set auto-reload vaule of baudrate generator
    
57.     AUXR = 0x14;            //Baudrate generator work in 1T mode
    
58.     IE2 = 0x01;             //Enable UART2 interrupt
    
59.     EA = 1;                 //Open master interrupt switch
    
60. 
    
61.     SendString("STC12C5A60S2\r\nUart2 Test !\r\n");
    
62.     while(1);
    
63. }
    
64. 
    
65. /*----------------------------
    
66. UART2 interrupt service routine
    
67. ----------------------------*/
    
68. void Uart2() interrupt 8
    
69. {
    
70.     if (S2CON & S2RI)
    
71.     {
    
72.         S2CON &= ~S2RI;     //Clear receive interrupt flag
    
73.         P0 = S2BUF;         //P0 show UART data
    
74.         P2 = (S2CON & S2RB8);//P2.2 show parity bit
    
75.     }
    
76.     if (S2CON & S2TI)
    
77.     {
    
78.         S2CON &= ~S2TI;     //Clear transmit interrupt flag
    
79.         busy = 0;           //Clear transmit busy flag
    
80.     }
    
81. }
    
82. 
    
83. /*----------------------------
    
84. Send a byte data to UART
    
85. Input: dat (data to be sent)
    
86. Output:None
    
87. ----------------------------*/
    
88. void SendData(BYTE dat)
    
89. {
    
90.     while (busy);           //Wait for the completion of the previous data is sent
    
91.     ACC = dat;              //Calculate the even parity bit P (PSW.0)
    
92.     if (P)                  //Set the parity bit according to P
    
93.     {
    
94. #if (PARITYBIT == ODD_PARITY)
    
95.         S2CON &= ~S2TB8;    //Set parity bit to 0
    
96. #elif (PARITYBIT == EVEN_PARITY)
    
97.         S2CON |= S2TB8;     //Set parity bit to 1
    
98. #endif
    
99.     }
    
100.     else
     
101.     {
     
102. #if (PARITYBIT == ODD_PARITY)
     
103.         S2CON |= S2TB8;     //Set parity bit to 1
     
104. #elif (PARITYBIT == EVEN_PARITY)
     
105.         S2CON &= ~S2TB8;    //Set parity bit to 0
     
106. #endif
     
107.     }
     
108.     busy = 1;
     
109.     S2BUF = ACC;            //Send data to UART2 buffer
     
110. }
     
111. 
     
112. /*----------------------------
     
113. Send a string to UART
     
114. Input: s (address of string)
     
115. Output:None
     
116. ----------------------------*/
     
117. void SendString(char *s)
     
118. {
     
119.     while (*s)              //Check the end of the string
     
120.     {
     
121.         SendData(*s++);     //Send current char and increment string ptr
     
122.     }
     
123. }
     
124. 
     

复制代码

并且我照STC官方的  S2CON &= ~S2RI;        操作也不行。