generated from hulk/gd32e23x_template_cmake_vscode
113 lines
3.8 KiB
C
113 lines
3.8 KiB
C
/**
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* ************************************************************************
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*
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* @file systick.c
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* @author GD32
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* @brief 通过 SysTick 定时器进行微秒级别和毫秒级别的延时函数
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*
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* ************************************************************************
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* @copyright Copyright (c) 2024 GD32
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* ************************************************************************
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*/
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#include "gd32e23x.h"
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#include "systick.h"
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volatile static float count_1us = 0;
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volatile static float count_1ms = 0;
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/**
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* ************************************************************************
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* @brief 配置 SysTick 定时器
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*
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*
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* ************************************************************************
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*/
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void systick_config(void)
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{
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//设置了 SysTick 定时器的时钟源为 HCLK/8
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systick_clksource_set(SYSTICK_CLKSOURCE_HCLK_DIV8);
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//计算了每微秒所需的 SysTick 计数值
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count_1us = (float)SystemCoreClock/8000000;
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//计算了每毫秒所需的 SysTick 计数值
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count_1ms = (float)count_1us * 1000;
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// 配置SysTick为1ms周期中断
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// 注意：SysTick_Config会自动设置时钟源为HCLK，所以需要使用SystemCoreClock/1000
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SysTick_Config(SystemCoreClock / 1000); // 1ms中断
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}
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/**
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* ************************************************************************
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* @brief delay_us 微秒延时函数
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*
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* @param[in] count 微秒值
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*
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* ************************************************************************
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*/
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void delay_us(uint32_t count)
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{
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uint32_t ctl;
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//设置 SysTick 计数器的装载值
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SysTick->LOAD = (uint32_t)(count * count_1us);
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//清零 SysTick 计数器，以确保计数器从零开始计数
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SysTick->VAL = 0x0000U;
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//使能 SysTick 定时器，开始进行计数
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SysTick->CTRL = SysTick_CTRL_ENABLE_Msk;
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//等待 SysTick 计数器的计数值达到装载值时退出
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do
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{
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ctl = SysTick->CTRL; //读取 CTRL 寄存器的值
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}while((ctl & SysTick_CTRL_ENABLE_Msk)&&!(ctl & SysTick_CTRL_COUNTFLAG_Msk));
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//循环退出，禁用 SysTick 定时器
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SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
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//将 SysTick 计数器的当前值清零，以便下次使用
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SysTick->VAL = 0x0000U;
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}
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/**
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* ************************************************************************
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* @brief delay_ms 毫秒延时函数
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*
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* @param[in] count 毫秒值
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*
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* ************************************************************************
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*/
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void delay_ms(uint32_t count)
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{
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uint32_t ctl;
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//设置 SysTick 计数器的装载值
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SysTick->LOAD = (uint32_t)(count * count_1ms);
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//清零 SysTick 计数器，以确保计数器从零开始计数
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SysTick->VAL = 0x0000U;
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//使能 SysTick 定时器，开始进行计数
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SysTick->CTRL = SysTick_CTRL_ENABLE_Msk;
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//等待 SysTick 计数器的计数值达到装载值时退出
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do
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{
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ctl = SysTick->CTRL; //读取 CTRL 寄存器的值
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}while((ctl&SysTick_CTRL_ENABLE_Msk)&&!(ctl & SysTick_CTRL_COUNTFLAG_Msk));
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//循环退出，禁用 SysTick 定时器
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SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
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//将 SysTick 计数器的当前值清零，以便下次使用
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SysTick->VAL = 0x0000U;
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}
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/**
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* ************************************************************************
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* @brief delay_ms_safe 毫秒延时函数（不干扰SysTick中断）
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* @details 使用简单循环实现延时，不会重新配置SysTick
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* @param[in] count 毫秒值
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* ************************************************************************
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*/
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void delay_ms_safe(uint32_t count)
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{
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// 基于系统时钟的简单循环延时
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// 这是一个粗略的估计，实际延时可能有偏差
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uint32_t loops_per_ms = SystemCoreClock / 8000; // 粗略估计
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for(uint32_t i = 0; i < count; i++) {
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for(volatile uint32_t j = 0; j < loops_per_ms; j++);
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}
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} |