C51学习 之 中断

 1 #include <reg52.h>
 2 
 3 sbit led = P1^0;
 4 
 5 void init()
 6 {
 7     TMOD = 0x01;   //定时器0
 8     TH0 = (65535 - 50000 * 12 / 12) / 256; //12MHz主频  定时1s  此处50ms
 9     TL0 = (65535 - 50000 * 12 / 12)% 256;
10     EA = 1;
11     ET0 = 1;
12     TR0 = 1;
13 }
14 
15 void on_T0Timer() interrupt 1
16 {
17     static unsigned int num = 0;
18     TH0 = (65535 - 50000 * 12 / 12) / 256;
19     TL0 = (65535 - 50000 * 12 / 12)% 256;
20   num++;
21     if (num == 20) {
22         num = 0;
23         led = ~led;
24     }
25 }
26 
27 int main()
28 {
29     init();
30     while(1);
31 }