最近调试了一个程序,使用的是keil5中Manage Run-Time Environment搭建的库。但是里面的延时函数就是个bug。函数原型与定义如下:
void HAL_Delay(__IO uint32_t Delay);
/**
* @brief This function provides accurate delay (in milliseconds) based
* on variable incremented.
* @note In the default implementation , SysTick timer is the source of time base.
* It is used to generate interrupts at regular time intervals where uwTick
* is incremented.
* @note This function is declared as __weak to be overwritten in case of other
* implementations in user file.
* @param Delay: specifies the delay time length, in milliseconds.
* @retval None
*/
__weak void HAL_Delay(__IO uint32_t Delay)
{
uint32_t tickstart = 0;
tickstart = HAL_GetTick();
while((HAL_GetTick() - tickstart) < Delay)
{
}
}
/**
* @brief Provides a tick value in millisecond.
* @note This function is declared as __weak to be overwritten in case of other
* implementations in user file.
* @retval tick value
*/
__weak uint32_t HAL_GetTick(void)
{
return uwTick;
}