led.c

LPC21xx ARM7 定时程序 定时控制LED

#include <LPC21xx.H>
#define LED 0x000001
typedef unsigned int uint32;
typedef unsigned char uint8;
void timer0_ISR (void) __attribute__ ((interrupt));
uint8 timer0Times = 0;
void timer0Init (void) {
    T0MR0 = 119999;                        /*匹配寄存器，120000-1，12000000为1秒*/
    T0MCR = 3;                             /*产生中断，重置TC*/
    T0TCR = 1;                             /*使能定时计数器0*/
    VICVectAddr0 = (unsigned long)timer0_ISR;        
    VICVectCntl0 = 0x20 | 4;               /*定时器计数器0为4号中断*/
    VICIntEnable = 0x00000010;             /*开定时计数器0中断*/
}
void timer0_ISR (void) {
	timer0Times++;
	uint32  i;
	if(timer0Times == 10){
		i=IO0SET;                         //读出当前LED2控制值
		if((i&LED)==0){
			IO0SET=LED; 
		}else{
			IO0CLR=LED;
		}
		timer0Times = 0;
	}
    T0IR = 1;                              /*清除定时器0中断*/
    VICVectAddr = 0;                       
}
int main(void) {
  PINSEL0 = 0;								/*设置引脚为GPIO */
  IO0DIR = LED;						/*将P0.0设置为输出 */
  IO0SET = LED;						/*将P0.0置1，也就是让led灭 */
  timer0Init();
  while (1)  {
  }
}