關于單片機中斷那些事,數碼管閃爍過快

ID:955347 · 發表于 2021-7-26 12:41

感覺進入中斷時間沒問題，但數碼管閃爍過快，代碼如下

#include <reg52.h>

sbit BEEP = P1^5； //跟中斷無關

bit flagls = 0;
unsigned char Ledbuf;
unsigned char T0RH = 0;
unsigned char T0RL = 0;
unsigned char code LedChar[] = {0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07, 0x7f, 0x6f};

void ConfigTimer0(unsigned int ms)       //配置T0
{
      unsigned long tmp;

      tmp = 11059200/12;
      tmp = (tmp*ms)/1000;
      tmp = 65536 - tmp;
      T0RH = (unsigned char)(tmp >> 8);
      T0RL = (unsigned char)tmp;

      TMOD &= 0xf0;
      TMOD |= 0x01;
      TH0=T0RH;
      TL0=T0RL;
      EA = 1;
      ET0 = 1;
      TR0 = 1;
}

void LedScan()       //在中斷中使用，每進中斷掃描一次
{
      P0 = 0x00;
      P2 = (P2&0xe3);
      P0 = Ledbuf;
}

void main()
{
      unsigned int i = 0;
      unsigned int sec = 0;

      ConfigTimer0(1);       //設置定時器1ms

      for(i = 0; i < 50000; i++)
      {
               BEEP = ~BEEP;
      }

      while(1)
      {
            if(flagls == 1)
            {
                     flagls = 0;
                     sec++;                               //每次進入sec加1
                     Ledbuf = LedChar[9 - sec%10];
            }
      }
}

void InterruptTimer0() interrupt 1
{
      static unsigned int tmr1s = 0;

      TH0=T0RH;                         //設置斷點看進入時間       第一次0.00266602s，第二次 0.00367405, 相差0.001s左右，進入正常
      TL0=T0RL;

      tmr1s++;
      if(tmr1s >= 1000);          //1s時改變flagls
      {
            tmr1s = 0;
            flagls = 1;
      }

      LedScan();
}