00. 目录

01. WDG概述

• WDG（Watchdog）看门狗

• 看门狗可以监控程序的运行状态，当程序因为设计漏洞、硬件故障、电磁干扰等原因，出现卡死或跑飞现象时，看门狗能及时复位程序，避免程序陷入长时间的罢工状态，保证系统的可靠性和安全性

• 看门狗本质上是一个定时器，当指定时间范围内，程序没有执行喂狗（重置计数器）操作时，看门狗硬件电路就自动产生复位信号

• STM32内置两个看门狗

独立看门狗（IWDG）：独立工作，对时间精度要求较低

窗口看门狗（WWDG）：要求看门狗在精确计时窗口起作用

02. 独立看门狗相关API

2.1 IWDG_WriteAccessCmd

/*** @brief  Enables or disables write access to IWDG_PR and IWDG_RLR registers.* @param  IWDG_WriteAccess: new state of write access to IWDG_PR and IWDG_RLR registers.*   This parameter can be one of the following values:*     @arg IWDG_WriteAccess_Enable: Enable write access to IWDG_PR and IWDG_RLR registers*     @arg IWDG_WriteAccess_Disable: Disable write access to IWDG_PR and IWDG_RLR registers* @retval None*/
void IWDG_WriteAccessCmd(uint16_t IWDG_WriteAccess)
功能:使能或者失能对寄存器 IWDG_PR 和 IWDG_RLR 的写操作
参数:IWDG_WriteAccess：对寄存器 IWDG_PR 和 IWDG_RLR 的写操作的新状态
返回值:无

2.2 IWDG_SetPrescaler

/*** @brief  Sets IWDG Prescaler value.* @param  IWDG_Prescaler: specifies the IWDG Prescaler value.*   This parameter can be one of the following values:*     @arg IWDG_Prescaler_4: IWDG prescaler set to 4*     @arg IWDG_Prescaler_8: IWDG prescaler set to 8*     @arg IWDG_Prescaler_16: IWDG prescaler set to 16*     @arg IWDG_Prescaler_32: IWDG prescaler set to 32*     @arg IWDG_Prescaler_64: IWDG prescaler set to 64*     @arg IWDG_Prescaler_128: IWDG prescaler set to 128*     @arg IWDG_Prescaler_256: IWDG prescaler set to 256* @retval None*/
void IWDG_SetPrescaler(uint8_t IWDG_Prescaler)
功能:设置 IWDG 预分频值
参数:IWDG_Prescaler：IWDG 预分频值
返回值:无    

2.3 IWDG_SetReload

/*** @brief  Sets IWDG Reload value.* @param  Reload: specifies the IWDG Reload value.*   This parameter must be a number between 0 and 0x0FFF.* @retval None*/
void IWDG_SetReload(uint16_t Reload)
功能:设置 IWDG 重装载值
参数:IWDG_Reload：IWDG 重装载值
返回值:无     

2.4 IWDG_ReloadCounter

/*** @brief  Reloads IWDG counter with value defined in the reload register*   (write access to IWDG_PR and IWDG_RLR registers disabled).* @param  None* @retval None*/
void IWDG_ReloadCounter(void)
功能:按照 IWDG 重装载寄存器的值重装载 IWDG 计数器
参数:无
返回值:无     

2.5 IWDG_Enable

/*** @brief  Enables IWDG (write access to IWDG_PR and IWDG_RLR registers disabled).* @param  None* @retval None*/
void IWDG_Enable(void)
功能:使能 IWDG
参数:无
返回值:无      

2.6 IWDG_GetFlagStatus

/*** @brief  Checks whether the specified IWDG flag is set or not.* @param  IWDG_FLAG: specifies the flag to check.*   This parameter can be one of the following values:*     @arg IWDG_FLAG_PVU: Prescaler Value Update on going*     @arg IWDG_FLAG_RVU: Reload Value Update on going* @retval The new state of IWDG_FLAG (SET or RESET).*/
FlagStatus IWDG_GetFlagStatus(uint16_t IWDG_FLAG)
功能:检查指定的 IWDG 标志位被设置与否
参数:IWDG_FLAG：待检查的 I2C 标志位
返回值:IWDG_FLAG 的新状态（SET 或者 RESET）       

2.7 RCC_GetFlagStatus

/*** @brief  Checks whether the specified RCC flag is set or not.* @param  RCC_FLAG: specifies the flag to check.*   *   For @b STM32_Connectivity_line_devices, this parameter can be one of the*   following values:*     @arg RCC_FLAG_HSIRDY: HSI oscillator clock ready*     @arg RCC_FLAG_HSERDY: HSE oscillator clock ready*     @arg RCC_FLAG_PLLRDY: PLL clock ready*     @arg RCC_FLAG_PLL2RDY: PLL2 clock ready      *     @arg RCC_FLAG_PLL3RDY: PLL3 clock ready                           *     @arg RCC_FLAG_LSERDY: LSE oscillator clock ready*     @arg RCC_FLAG_LSIRDY: LSI oscillator clock ready*     @arg RCC_FLAG_PINRST: Pin reset*     @arg RCC_FLAG_PORRST: POR/PDR reset*     @arg RCC_FLAG_SFTRST: Software reset*     @arg RCC_FLAG_IWDGRST: Independent Watchdog reset*     @arg RCC_FLAG_WWDGRST: Window Watchdog reset*     @arg RCC_FLAG_LPWRRST: Low Power reset* *   For @b other_STM32_devices, this parameter can be one of the following values:        *     @arg RCC_FLAG_HSIRDY: HSI oscillator clock ready*     @arg RCC_FLAG_HSERDY: HSE oscillator clock ready*     @arg RCC_FLAG_PLLRDY: PLL clock ready*     @arg RCC_FLAG_LSERDY: LSE oscillator clock ready*     @arg RCC_FLAG_LSIRDY: LSI oscillator clock ready*     @arg RCC_FLAG_PINRST: Pin reset*     @arg RCC_FLAG_PORRST: POR/PDR reset*     @arg RCC_FLAG_SFTRST: Software reset*     @arg RCC_FLAG_IWDGRST: Independent Watchdog reset*     @arg RCC_FLAG_WWDGRST: Window Watchdog reset*     @arg RCC_FLAG_LPWRRST: Low Power reset*   * @retval The new state of RCC_FLAG (SET or RESET).*/
FlagStatus RCC_GetFlagStatus(uint8_t RCC_FLAG)
功能:检查指定的 RCC 标志位设置与否
参数:RCC_FLAG：待检查的 RCC 标志位
返回值:RCC_FLAG 的新状态（SET 或者 RESET）   

03. 独立看门狗接线图

04. 独立看门狗程序示例1

main.c

#include "stm32f10x.h"#include "delay.h"
#include "oled.h"int main(void){	//初始化OLED_Init();OLED_ShowString(1, 1, "IWDG TEST");if (RCC_GetFlagStatus(RCC_FLAG_IWDGRST) == SET){OLED_ShowString(2, 1, "IWDGRST");delay_ms(500);OLED_ShowString(2, 1, "       ");delay_ms(100); RCC_ClearFlag();}else{OLED_ShowString(3, 1, "RST");delay_ms(500);OLED_ShowString(3, 1, "       ");delay_ms(100); }//写使能IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);//设置预分频IWDG_SetPrescaler(IWDG_Prescaler_16);//设置重装载值  1000 = 1 / 40K * 16 * x   x = 2500IWDG_SetReload(2499);//喂狗IWDG_ReloadCounter();//看门狗使能IWDG_Enable();while(1){//喂狗IWDG_ReloadCounter();delay_ms(1800);}return 0;}

05. 独立看门狗程序示例2

main.c

#include "stm32f10x.h"#include "delay.h"
#include "oled.h"
#include "key.h"int main(void){	//初始化OLED_Init();//按键初始化key_init();OLED_ShowString(1, 1, "IWDG TEST");if (RCC_GetFlagStatus(RCC_FLAG_IWDGRST) == SET){OLED_ShowString(2, 1, "IWDGRST");delay_ms(500);OLED_ShowString(2, 1, "       ");delay_ms(100); RCC_ClearFlag();}else{OLED_ShowString(3, 1, "RST");delay_ms(500);OLED_ShowString(3, 1, "   ");delay_ms(100); }//写使能IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);//设置预分频IWDG_SetPrescaler(IWDG_Prescaler_16);//设置重装载值  1000 = 1 / 40K * 16 * x   x = 2500IWDG_SetReload(2499);//喂狗IWDG_ReloadCounter();//看门狗使能IWDG_Enable();while(1){key_scan();//喂狗IWDG_ReloadCounter();OLED_ShowString(4, 1, "FEED");delay_ms(200);OLED_ShowString(4, 1, "    ");delay_ms(600); }return 0;}

06. 窗口看门狗相关API

6.1 WWDG_DeInit

/*** @brief  Deinitializes the WWDG peripheral registers to their default reset values.* @param  None* @retval None*/
void WWDG_DeInit(void)
功能:将外设 WWDG 寄存器重设为缺省值
参数:无
返回值:无

6.2 WWDG_SetPrescaler

/*** @brief  Sets the WWDG Prescaler.* @param  WWDG_Prescaler: specifies the WWDG Prescaler.*   This parameter can be one of the following values:*     @arg WWDG_Prescaler_1: WWDG counter clock = (PCLK1/4096)/1*     @arg WWDG_Prescaler_2: WWDG counter clock = (PCLK1/4096)/2*     @arg WWDG_Prescaler_4: WWDG counter clock = (PCLK1/4096)/4*     @arg WWDG_Prescaler_8: WWDG counter clock = (PCLK1/4096)/8* @retval None*/
void WWDG_SetPrescaler(uint32_t WWDG_Prescaler)
功能:设置 WWDG 预分频值值
参数:WWDG_Prescaler：指定 WWDG 预分频
返回值:无

6.3 WWDG_SetWindowValue

/*** @brief  Sets the WWDG window value.* @param  WindowValue: specifies the window value to be compared to the downcounter.*   This parameter value must be lower than 0x80.* @retval None*/
void WWDG_SetWindowValue(uint8_t WindowValue)
功能:设置 WWDG 窗口值
参数:WindowValue r：指定的窗口值。该参数取值必须在 0x40 与 0x7F 之间。
返回值:无    

6.4 WWDG_EnableIT

/*** @brief  Enables the WWDG Early Wakeup interrupt(EWI).* @param  None* @retval None*/
void WWDG_EnableIT(void)
功能:使能 WWDG 早期唤醒中断（EWI）
参数:无
返回值:无      

6.5 WWDG_SetCounter

/*** @brief  Sets the WWDG counter value.* @param  Counter: specifies the watchdog counter value.*   This parameter must be a number between 0x40 and 0x7F.* @retval None*/
void WWDG_SetCounter(uint8_t Counter)
功能:设置 WWDG 计数器值
参数:Counter：指定看门狗计数器值。该参数取值必须在 0x40 与 0x7F 之间。
返回值:无      

6.6 WWDG_Enable

/*** @brief  Enables WWDG and load the counter value.                  * @param  Counter: specifies the watchdog counter value.*   This parameter must be a number between 0x40 and 0x7F.* @retval None*/
void WWDG_Enable(uint8_t Counter)
功能:使能 WWDG 并装入计数器值
参数:Counter：指定看门狗计数器值。该参数取值必须在 0x40 与 0x7F 之间。
返回值:无      

6.7 WWDG_GetFlagStatus

/*** @brief  Checks whether the Early Wakeup interrupt flag is set or not.* @param  None* @retval The new state of the Early Wakeup interrupt flag (SET or RESET)*/
FlagStatus WWDG_GetFlagStatus(void)
功能:检查 WWDG 早期唤醒中断标志位被设置与否
参数:无
返回值:早期唤醒中断标志位的新状态（SET 或者 RESET）      

6.8 WWDG_ClearFlag

/*** @brief  Clears Early Wakeup interrupt flag.* @param  None* @retval None*/
void WWDG_ClearFlag(void)
功能:清除早期唤醒中断标志位
参数:无
返回值:无

07. 窗口看门狗接线图

08. 窗口看门狗程序示例

main.c

#include "stm32f10x.h"#include "delay.h"
#include "oled.h"
#include "key.h"int main(void){	//初始化OLED_Init();//按键初始化key_init();//开启WWDG时钟RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);OLED_ShowString(1, 1, "WWDG TEST");if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) == SET){OLED_ShowString(2, 1, "WWDGRST");delay_ms(500);OLED_ShowString(2, 1, "       ");delay_ms(100); RCC_ClearFlag();}else{OLED_ShowString(3, 1, "RST");delay_ms(500);OLED_ShowString(3, 1, "   ");delay_ms(100); }//设置预分频WWDG_SetPrescaler(WWDG_Prescaler_8);//设置窗口值WWDG_SetWindowValue(21 | 0x40);//使能看门狗WWDG_Enable(0x40 | 54);while(1){key_scan();OLED_ShowString(4, 1, "FEED");delay_ms(10);OLED_ShowString(4, 1, "    ");delay_ms(10); //喂狗WWDG_SetCounter(0x40 | 54);}return 0;}

09. 程序示例代码下载

38-独立看门狗.rar

39-窗口看门狗.rar

10. 附录

参考: 【STM32】江科大STM32学习笔记汇总