autoswitch.c

这是一个用于视频切换的控制程序,采用AT89C51芯片,KEIL 51开发

//for auto switch
//2004-5-23
#include "reg52.h"
#include "main.h"
bit TimerFlag=0;
extern bit fgledflash;
extern unsigned char data ledbuffer_h;
extern unsigned char data ledbuffer_l;
extern unsigned char data auto_counter;
extern unsigned int TimeCounter;

void Timer1ISR_1(void) interrupt 3 using 2
{
 TH1=0x3c;
 TL1=0xb0;
 if(TimeCounter!=0)
 TimeCounter--;
 else
 {
  TimeCounter=auto_counter*20;
  TimerFlag=1;
 } 
}
  


 

void AutoSwitch(void)
{
 if(!TimerFlag ||fgledflash)
 {
  EA=1;
  ET1=1;
  TR1=1;
 }

 else
 {
  TimerFlag=0;
  ledbuffer_h=0;
 
   if(ledbuffer_l<8)
      ledbuffer_l++;
   else
   ledbuffer_l=1;  

	   P0=(ledbuffer_l-1) | 0xf8;
       INH_1=0;
       INH_2=1;

  } 
}