k60驱动代码学习（5）

//systick   记时，延时
#include "include.h"
#include "MK60_SYSTICK.h"
#define EACH_PER_MS    25   //每隔 25 ms 中断一次  systick 定时器是24位向下计数的定时器  最大装载值16777215 / 600 000 000= 0.2796 最大计时27ms

struct time{
	
    uint32_t fac_us;                  //us分频系数
	uint32_t fac_ms;                  //ms分频系数
	volatile uint32_t millisecond;   //ms
	uint64_t microsecond;             //us
	uint8_t ms_per_tick;              //1ms多少systick计数次数
	
}timer;
/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】初始化systick计数器  
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】无
【参数值】无     
【例子  】systime.init();                     //开启systick定时器 
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
static void systime_init()
{
	timer.fac_us = core_clk;
	timer.fac_ms = core_clk * 1000;
	timer.ms_per_tick = EACH_PER_MS;
    timer.millisecond = 100;
	SysTick_Config(timer.fac_ms * timer.ms_per_tick );   //开启systick中断
}
/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】systick  中断服务函数 
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】无
【参数值】无     
【例子  】
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
void SysTick_Handler(void)
{
	timer.millisecond += timer.ms_per_tick;
}

/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】systick  获取当前ms值 
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】当前ms值
【参数值】无     
【例子  】systime.get_time_ms();         //计时功能  得到当前时间 ms   
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
static uint32_t get_current_time_ms(void)
{
    uint32_t val = SysTick->VAL;
	return timer.millisecond -  val/timer.fac_ms;
}
/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】systick  获取当前ms值 
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】当前ms值
【参数值】无     
【例子  】systime.get_time_us();         //计时功能  得到当前时间 us   
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
static uint64_t get_current_time_us(void)
{
    uint32_t val = SysTick->VAL;
	return (uint64_t)((uint64_t)(timer.millisecond * 1000) -  val / timer.fac_us);
}

/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】systick  延时us 
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】无
【参数值】无     
【例子  】systime.delay_us(1000000);         //延时功能  延时1s
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
static void delay_us( uint32_t us)     
{
    uint64_t now = systime.get_time_us();
	uint64_t end_time = now + us - 1;
	while( systime.get_time_us() < end_time)
    {
        ;
    }
}

/*LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
【作  者】LQ-005
【功能说明】systick  延时ms
【软件版本】V1.0
【最后更新】2019年03月12日 
【返回值】无
【参数值】无     
【例子  】systime.delay_ms(1000);         //延时功能 延时1s 
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ*/
static void delay_ms( uint16_t ms) 
{
	systime.delay_us(ms * 1000);
}

systime_t  systime = 
{
	systime_init,
	get_current_time_us,
	get_current_time_ms,
	delay_us,
	delay_ms
};

来源：CSDN

作者：他 不懂

链接：https://blog.csdn.net/weixin_44146373/article/details/104212857