#include "delay.h"

/*
  @ brief  延时函数
  @ param
  @ return
  @ note   2022-5-23
*/
void delay_us(int us)
{
    uint32_t start, now, delta, reload, us_tick;
    start = SysTick->VAL;
    reload = SysTick->LOAD;
    us_tick = SystemCoreClock / 1000000UL;
    do
    {
      now = SysTick->VAL;
      delta = start > now ? start - now : reload + start - now;
    } while (delta < us_tick * us);
}

void delay_ms(int ms)//封装了，不能直接替换，不知道为什么
{
  rt_thread_mdelay(ms);
}