Question

这段代码通过计算特定时间延迟的INT0外部中断数来写入显示速度，以mph为单位工作，即只显示“读出：” 然后什么也没有。我在c51开发工具中看到了8051衍生品页面。它告诉我没有必要的信息。 http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.kui0002a/c51_dv_8051deriv.htm 我不明白为什么有时写它 void ex0_isr（void）interrupt 0 使用2

有人可以帮我理解哪里错了吗？模拟工作正常。

//Calculating speed 

 #include <reg51.h>
 #include <string.h>


 void read(unsigned int q);
 void delay(void);
 void delay1(unsigned long int time);
 void SerInit();
 void SerTx(unsigned char x);
 void SerTx_str(unsigned char msg[]);

 unsigned char msg[]="Speed=  ";
 unsigned char buffer[12];
 sbit in_port=P3^2;
 sbit EDGT=TCON^0;
 unsigned char volatile count;
 unsigned int q;

  void ex0_isr(void) interrupt 0 
  {
    count++;
  }

  void timer0(void) interrupt 1
  {
     TR0=0;
  {



 void main()
  {

    SerInit();                 //serial initialisation
    SerTx_str("Read out:");    //send string to hyperterminal
    SerTx('\n');
    delay1(20);                //delay using loop
    SerTx('\r');
    in_port=1;             //input port pin
    EDGT=1;                //make IT0 =1 an edge triggered
    while(1)
    {
      count=0;             //initialize count
      IE=IE|0x81;          //enable global and INT0 
      delay();             //delay using timers for a time to measure  count
      SerTx_str("Dbg");   //check
      IE=IE&0xFE;          //disable INT0         
      q=count;               
      read(q);             //function called for ASCII conversion
      SerTx_str(msg);      //send message to terminal
      SerTx_str(buffer);   // send count to terminal
      SerTx('\n');
      delay1(2000);
      SerTx('\r');
    }
  }


 void read( unsigned int q)
  {
    unsigned int d1,d2,d3;
    d1=q%10;
    q=q/10;
    d2=q%10;
    d3=q/10;

    buffer[0]=d3+'0';
    buffer[1]=d2+'0';
    buffer[2]=d1+'0';
  }

  void delay(void)
  {
    unsigned int i;
    for(i=0;i<45;i++)  
    {
        TMOD=0x01;      //Timer 0, mode1(16 bit)
        TL0=0xFD;       //load TL0
        TH0=0x4B;       //load TH0 
        IE=IE|0x02;     //enable Timer 0 interrupt
        TR0=1;          //turn on Timer 0
       do
        {
         q=count;
        }
       while(TF0==0);   

    //if there's overflow ie, TF=1, goto interrupt 1 
    //
    //> TMOD=0x01;
      >  TL0=0xFD;
      >  TH0=0x4B;
      >  TR0=1;
      >  while(TF==0);
      >   TR0=0;
      >   TF0=0;  // previous code

    }
  }

Answer 1

我的猜测是通过这样做：

IE=0x81;

您不小心禁用了计时器中断，这意味着您的delay（）函数永远不会返回。我怀疑你可能想做这样的事情：

IE = IE | 0x01;          // enable INT0
delay();                 // delay using timers for a time to measure  count
IE = IE & 0xFE;          // disable INT0

c中8051的外部中断

1 个答案: