#include "pt_timer.h" 
#include "task.h"  

#define clock_time get_system_ms
//启动定时器
void timer_set(struct timer *t, unsigned long interval)
{ 
  t->interval = interval;       // 存储需要延时的us数
  t->start = clock_time();     //获取当前的us值
}

// 定时器超时判断
unsigned char  timer_expired(struct timer *t)
{ 
    unsigned long  now =  clock_time() ;
    unsigned long  err = now - t->start;
    // clock_time()会获取当前的tick值, 如果当前值-开始值超过了延时的tick数, 那么就是超时了
    unsigned char  overTime =  err>=  t->interval;
    _nop_();
    return  overTime; // 思考:溢出会如何呢?  //没问题,负数-正数仍然是一个正数
}

 

/*
//延时,必须是开中断状态下
void delay_ms(int t_ms)
{
    struct pt pt1;
    static struct timer  input_timer;  
    
    timer_set(&input_timer,t_ms);
    while(!timer_expired(&input_timer)); 
}
*/