1、GD32F470ZK延时函数

一、延时函数初始化

//配置systick的时钟
void Delay_Init(void)
{
	systick_clksource_set(SYSTICK_CLKSOURCE_HCLK_DIV8);
	count_1us = (float)(SystemCoreClock / 8 / 1000 / 1000);
}

二、us延时

void Delay_Us(uint32_t us)
{
	uint32_t ctl;
	SysTick ->LOAD = (uint32_t)(us * count_1us);
	SysTick ->VAL = 0x0000U;
	SysTick ->CTRL |= SysTick_CTRL_ENABLE_Msk;
	do{
		ctl = SysTick ->CTRL;
	}while((ctl & SysTick_CTRL_ENABLE_Msk) && !(ctl & SysTick_CTRL_COUNTFLAG_Msk));
	
	//停止
	SysTick ->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
	SysTick ->VAL = 0x0000U;
}

三、ms延时

void Delay_Ms(uint32_t ms)
{
	while(ms--)
	{
		Delay_Us(1000);
	}
}