STM32F10X delay函数的记录
作者：互联网
非RTOS 的delay功能实现 时钟使用SystemInit()初始化(3.5版本库函数)
uint32_t SystemCoreClock = SYSCLK_FREQ_72MHz; /*!< System Clock Frequency (Core Clock) */
#include "delay.h"
static uint16_t factor_us; //根据系统时钟，延时1uS的计数值
static uint16_t factor_ms; //根据系统时钟，延时1mS的计数值
//---------------------------------------------------------------------------
//函数功能:延时函数初始化
//描述:
// 1.SYSCLOCK：系统时钟
// 2.
// 执行周期:
//日期:2017/10/22 11:53:11
//---------------------------------------------------------------------------
void DelayInit(void)
{
SysTick->CTRL &= 0xfffffffb; //清除BIT2 ，0 外部时钟源(STCLK) 1 内核时钟(FCLK)
factor_us = SystemCoreClock/8000000; //系统时钟8分频
factor_ms = factor_us*1000;
}
//---------------------------------------------------------------------------
//函数功能:延时函数微秒级
//描述:
// 1.SYSCLOCK：系统时钟
// 2.
// 执行周期:
//日期:2017/10/22 11:53:11
//---------------------------------------------------------------------------
void delay_us(uint16_t delay_us_cnt)
{
uint32_t SysTick_CTRL_buf_us;
SysTick->LOAD = delay_us_cnt * factor_us; //装载重载计数器初始值
SysTick->VAL = 0; //清零计数器初始值
SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; //使能systick 定时器
//开始计时
do
{
SysTick_CTRL_buf_us = SysTick->CTRL ;
}while( (SysTick_CTRL_buf_us&0x01) && ( !(SysTick_CTRL_buf_us&(1<<16)) ) );
SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; //关闭计数器
SysTick->VAL = 0; //清空计数器
}
//---------------------------------------------------------------------------
//函数功能:延时函数微秒级
//描述:
// 1.SYSCLOCK：系统时钟
// 2.
// 执行周期:
//日期:2017/10/22 11:53:11
//---------------------------------------------------------------------------
void delay_ms(uint16_t delay_ms_cnt)
{
uint32_t SysTick_CTRL_buf_ms;
SysTick->LOAD = delay_ms_cnt * factor_ms; //装载重载计数器初始值
SysTick->VAL = 0; //清零计数器初始值
SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; //使能systick 定时器
//开始计时
do
{
SysTick_CTRL_buf_ms = SysTick->CTRL ;
}while( (SysTick_CTRL_buf_ms&0x01) && ( !(SysTick_CTRL_buf_ms&(1<<16)) ) );
SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; //关闭计数器
SysTick->VAL = 0; //清空计数器
}
SysTick的库函数部分,来自Core_cm3.h
/** @addtogroup CMSIS_CM3_SysTick CMSIS CM3 SysTick
memory mapped structure for SysTick
@{
*/
typedef struct
{
__IO uint32_t CTRL; /*!< Offset: 0x00 SysTick Control and Status Register *///控制与状态寄存器
__IO uint32_t LOAD; /*!< Offset: 0x04 SysTick Reload Value Register *///重装值寄存器
__IO uint32_t VAL; /*!< Offset: 0x08 SysTick Current Value Register *///当前值寄存器
__I uint32_t CALIB; /*!< Offset: 0x0C SysTick Calibration Register *///校准寄存器
} SysTick_Type;
/* SysTick Control / Status Register Definitions */
#define SysTick_CTRL_COUNTFLAG_Pos 16 /*!< SysTick CTRL: COUNTFLAG Position */
#define SysTick_CTRL_COUNTFLAG_Msk (1ul << SysTick_CTRL_COUNTFLAG_Pos) /*!< SysTick CTRL: COUNTFLAG Mask */
#define SysTick_CTRL_CLKSOURCE_Pos 2 /*!< SysTick CTRL: CLKSOURCE Position */
#define SysTick_CTRL_CLKSOURCE_Msk (1ul << SysTick_CTRL_CLKSOURCE_Pos) /*!< SysTick CTRL: CLKSOURCE Mask */
#define SysTick_CTRL_TICKINT_Pos 1 /*!< SysTick CTRL: TICKINT Position */
#define SysTick_CTRL_TICKINT_Msk (1ul << SysTick_CTRL_TICKINT_Pos) /*!< SysTick CTRL: TICKINT Mask */
#define SysTick_CTRL_ENABLE_Pos 0 /*!< SysTick CTRL: ENABLE Position */
#define SysTick_CTRL_ENABLE_Msk (1ul << SysTick_CTRL_ENABLE_Pos) /*!< SysTick CTRL: ENABLE Mask */
/* SysTick Reload Register Definitions */
#define SysTick_LOAD_RELOAD_Pos 0 /*!< SysTick LOAD: RELOAD Position */
#define SysTick_LOAD_RELOAD_Msk (0xFFFFFFul << SysTick_LOAD_RELOAD_Pos) /*!< SysTick LOAD: RELOAD Mask */ //最大装载值24字节
/* SysTick Current Register Definitions */
#define SysTick_VAL_CURRENT_Pos 0 /*!< SysTick VAL: CURRENT Position */
#define SysTick_VAL_CURRENT_Msk (0xFFFFFFul << SysTick_VAL_CURRENT_Pos) /*!< SysTick VAL: CURRENT Mask */ //最大装载值24字节
/* SysTick Calibration Register Definitions */
#define SysTick_CALIB_NOREF_Pos 31 /*!< SysTick CALIB: NOREF Position */
#define SysTick_CALIB_NOREF_Msk (1ul << SysTick_CALIB_NOREF_Pos) /*!< SysTick CALIB: NOREF Mask */
#define SysTick_CALIB_SKEW_Pos 30 /*!< SysTick CALIB: SKEW Position */
#define SysTick_CALIB_SKEW_Msk (1ul << SysTick_CALIB_SKEW_Pos) /*!< SysTick CALIB: SKEW Mask */
#define SysTick_CALIB_TENMS_Pos 0 /*!< SysTick CALIB: TENMS Position */
#define SysTick_CALIB_TENMS_Msk (0xFFFFFFul << SysTick_VAL_CURRENT_Pos) /*!< SysTick CALIB: TENMS Mask */
/*@}*/ /* end of group CMSIS_CM3_SysTick */
SysTick寄存器地址定义
#define SCS_BASE (0xE000E000) /*!< System Control Space Base Address */ #define SysTick_BASE (SCS_BASE + 0x0010) /*!< SysTick Base Address */ #define SysTick ((SysTick_Type *) SysTick_BASE) /*!< SysTick configuration struct */
SysTick function 函数
/* ################################## SysTick function ############################################ */
#if (!defined (__Vendor_SysTickConfig)) || (__Vendor_SysTickConfig == 0)
/**
* @brief Initialize and start the SysTick counter and its interrupt.
*
* @param ticks number of ticks between two interrupts
* @return 1 = failed, 0 = successful
*
* Initialise the system tick timer and its interrupt and start the
* system tick timer / counter in free running mode to generate
* periodical interrupts.
*/
static __INLINE uint32_t SysTick_Config(uint32_t ticks)
{
if (ticks > SysTick_LOAD_RELOAD_Msk) return (1); /* Reload value impossible */
SysTick->LOAD = (ticks & SysTick_LOAD_RELOAD_Msk) - 1; /* set reload register */
NVIC_SetPriority (SysTick_IRQn, (1<<__NVIC_PRIO_BITS) - 1); /* set Priority for Cortex-M0 System Interrupts */
SysTick->VAL = 0; /* Load the SysTick Counter Value */
SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk |
SysTick_CTRL_TICKINT_Msk |
SysTick_CTRL_ENABLE_Msk; /* Enable SysTick IRQ and SysTick Timer */
return (0); /* Function successful */
}
#endif
MISC.h宏定义时钟来源及分频
#define SysTick_CLKSource_HCLK_Div8 ((uint32_t)0xFFFFFFFB)
#define SysTick_CLKSource_HCLK ((uint32_t)0x00000004)
#define IS_SYSTICK_CLK_SOURCE(SOURCE) (((SOURCE) == SysTick_CLKSource_HCLK) || \
((SOURCE) == SysTick_CLKSource_HCLK_Div8))
Systick的时钟来源有两个:HCLK 或者HCLK的8分频
SysTick 中断
中断向量定义在startup_stm32f10x_hd.s文件 line77
DCD SysTick_Handler ; SysTick Handler
中断函数定义在stm32f10x_it.c lin135
/**
* @brief This function handles SysTick Handler.
* @param None
* @retval None
*/
void SysTick_Handler(void)
{
}
标签：函数,CTRL,STM32F10X,us,delay,Msk,ms,SysTick,uint32 来源： https://www.cnblogs.com/-iting/p/12635385.html