main.c

来自「keil 编写的89c51几个程序函数,用于键盘扫描,蜂鸣器,计时等功能,简单易」· C语言 代码 · 共 58 行

#include "reg51.h"
#include "pin.h"



//调试标识
bit a = 0;

//
sbit Sound = P3^7;
//全局标识
unsigned int t10ms;//10ms计数



void inttime0(void);//timer0 initialize,set time as 0.01s





main()
{

inttime0();
EA = 1;
while (1)
   {
    if (t10ms == 100)
	   {
         t10ms =0 ;
         a = 1;
         Sound = 1;
	   }
   }


}


time0() interrupt 1
{
TH0 = -10000/256;
TL0 = -10000%256;
t10ms++;
}


void inttime0(void)
{
TMOD=(TMOD&0xf0)|0x01;//MODE 1
  ET0=1;//
  TH0 = -10000/256;
  TL0 = -10000%256;
  TR0=1;//

}