定时器外部中断

 1 #include <reg52.h>
 2 typedef unsigned char u8;
 3 typedef unsigned int u16;
 4 sbit key = P3^2;
 5 sbit led = P1^0;
 6 
 7 void delay(void);
 8 void main(void)
 9 {
10     TCON |= 0x01
11     IE = 0x81;
12     while(1);
13 }
14 void ext_int0(void) interrupt 0
15 {
16     delay(10);
17     if (key == 0)
18     {
19      led =~led;
20     }
21     while(!key);
22 }