/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
/* Initialize LED1 and Key Button mounted on STM3210X-EVAL board */
STM_EVAL_LEDInit(LED1);
STM_EVAL_LEDInit(LED2);
STM_EVAL_PBInit(BUTTON_KEY, BUTTON_MODE_EXTI);
/* Check if the system has resumed from WWDG reset */
if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET)
{
/* WWDGRST flag set */
/* Turn on LED1 */
STM_EVAL_LEDOn(LED1);
/* Clear reset flags */
RCC_ClearFlag();
}
else
{
/* WWDGRST flag is not set */
/* Turn off LED1 */
STM_EVAL_LEDOff(LED1);
}
/* NVIC configuration */
NVIC_Configuration();
/* WWDG configuration */
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/* On Value line devices, WWDG clock counter = (PCLK1 (24MHz)/4096)/8 = 732 Hz (~1366 æs) */
/* On other devices, WWDG clock counter = (PCLK1(36MHz)/4096)/8 = 1099 Hz (~910 æs) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 65 */
WWDG_SetWindowValue(65);
/* On Value line devices, Enable WWDG and set counter value to 127, WWDG timeout = ~1366 æs * 64 = 87.42 ms */
/* On other devices, Enable WWDG and set counter value to 127, WWDG timeout = ~910 æs * 64 = 58.25 ms */
WWDG_Enable(127);
/* Clear EWI flag */
WWDG_ClearFlag();
/* Enable EW interrupt */
WWDG_EnableIT();
while (1)
{
}
}
THD_FUNCTION(Thread0, arg)
{
(void)arg;
if (RCC->CSR & RCC_CSR_WWDGRSTF)
{
/* WWDGRST flag set */
serDbg("\r\n**WWDG Reset!**\r\n\r\n");
/* Clear reset flags */
RCC->CSR |= RCC_CSR_RMVF;
}
/* WWDG clock counter = (PCLK1 (48MHz)/4096)/8 = 1464Hz (~683 us) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 126; WWDG counter should be refreshed only when the counter
is below 126 (and greater than 64) otherwise a reset will be generated */
WWDG_SetWindowValue(126);
/* Freeze WWDG while core is stopped */
DBGMCU->APB1FZ |= DBGMCU_APB1_FZ_DBG_WWDG_STOP;
/* Enable WWDG and set counter value to 127, WWDG timeout = ~683 us * 64 = 43.7 ms
In this case the refresh window is: ~683 * (127-126)= 0.683ms < refresh window < ~683 * 64 = 43.7ms
*/
WWDG_Enable(127);
serDbg("WWDG Started\r\n");
while (true)
{
chThdSleepMilliseconds(25);
palTogglePad(GPIOC, GPIOC_LED3); /* Watchdog heartbeat */
WWDG_SetCounter(127);
}
}
void PhotonWdgs::begin(bool _enableWwdg,bool _enableIwdg,unsigned long _timeout, TIMid id)
{
if(!_enableWwdg && !_enableIwdg) {
// nothing to do ...
return;
}
PhotonWdgs::_aliveCount = 0;
PhotonWdgs::_timeoutval = _timeout / 10;
RCC_LSICmd(ENABLE); //LSI is needed for Watchdogs
PhotonWdgs::_wdgTimer.begin(PhotonWdgs::_tickleWDGs, 20, hmSec, id);
// OTA updates won't work with watchdog enabled
System.disableUpdates();
PhotonWdgs::_wwdgRunning = _enableWwdg;
if(_enableWwdg) {
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
WWDG_SetPrescaler(WWDG_Prescaler_8);
WWDG_SetWindowValue(0x7F);
WWDG_Enable(0x7F);
}
PhotonWdgs::_iwdgRunning = _enableIwdg;
if(_enableIwdg) {
IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
IWDG_SetPrescaler(IWDG_Prescaler_256);
IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
IWDG_SetReload(0xFFF);
IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
IWDG_Enable();
}
}
/*************************************************************
* WWDT Initialization
**************************************************************/
void WWDG_Init()
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
// Deinitializes WWDG peripheral registers
#if(STRCMP($ResetEn$, DISABLE) == 0)
WWDG_DeInit();
#endif
// Sets Prescaler value of the WWDG.
WWDG_SetPrescaler($PreValue$);
// Sets Window value of the WWDG.
WWDG_SetWindowValue($WindowValue$);
// Sets Counter value of the WWDG.
WWDG_SetCounter($CounterValue$);
// Enable WWDG and set counter value
WWDG_Enable($CounterValue$);
//Enable EW interrupt
#if((STRCMP($IntEn$,DISABLE)) == 0)
WWDG_ClearFlag();
WWDG_EnableIT();
#endif
}
/*
*********************************************************************************************************
* 函 数 名: bsp_InitWwdg
* 功能说明: 初始化窗口看门狗。
* 形 参:
* 返 回 值: 无
*********************************************************************************************************
*/
static void bsp_InitWwdg(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* 打开窗口看门狗时钟，APB1低速时钟36MHz*/
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG , ENABLE);
/* 使能看门狗中断 */
NVIC_InitStructure.NVIC_IRQChannel = WWDG_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 10;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* 设置窗口看门狗时钟为 WWDG_CLK = (PCLK1 (36MHz)/4096)/8 = 1152 Hz (~868 us), 最大超时时间: 780 * 64 = 58.25ms */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* 设置窗口看门狗窗口上限, 计数器小于0x50时，才能重装载计数器 */
/* Enable WWDG and set counter value to 127。In this case the refresh window is:
WWDG_FRQ = 1/WWDG_CLK;
~WWDG_FRQ * (WWDG_RELOAD_VALUE-WWDG_RELOAD_WTIME_VALUE) < refresh window < ~WWDG_FRQ * (WWDG_RELOAD_VALUE-0x3F)
*/
WWDG_SetWindowValue(WWDG_RELOAD_WTIME_VALUE);
/* 使能窗口看门狗计数器，并设置计数初值为0x7F */
WWDG_Enable(WWDG_RELOAD_VALUE);
/* 清除窗口看门狗标志 */
WWDG_ClearFlag();
/* 使能窗口看门狗中断 */
WWDG_EnableIT();
/* 置位窗口看门口标志 */
WWDG_EN_MARK = 1;
}
/**-----------------------------------------------------------------------------
* @brief Initialisation du watchdog Windows.
*
* param[in] Timeout_ms Duree du timeout watchdog en ms.
*/
void WDG_InitWWDG(uint16_t Timeout_ms){
RCC_ClocksTypeDef xRCC_Clocks;
uint32_t ulClock_kHz;
WWDG_DeInit();
// Initialisation des variables
WWDG_Reload = Timeout_ms;
WWDG_Cnt = Timeout_ms;
// Activation horloges
RCC_APB1PeriphResetCmd(RCC_APB1Periph_WWDG, DISABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
// Configuration interruption
WWDG_EnableIT();
#ifdef configLIBRARY_KERNEL_INTERRUPT_PRIORITY
NVIC_InitStructure.NVIC_IRQChannel = WWDG_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = configLIBRARY_KERNEL_INTERRUPT_PRIORITY;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init( &NVIC_InitStructure );
#else
NVIC_EnableIRQ(WWDG_IRQn);
#endif
// Configuration timeout
WWDG_SetPrescaler(WWDG_Prescaler_8);
WWDG_SetWindowValue(0x7F);
// Activation
WWDG_Enable(0x7F);
WDG_Refresh();
}
void WWDG_Configuration(void)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
WWDG_SetPrescaler(WWDG_Prescaler_8); // WWDG clock counter = (PCLK1/4096)/8 = 244 Hz (~4 ms)
WWDG_SetWindowValue(0x41); // Set Window value to 0x41
WWDG_Enable(0x50); // Enable WWDG and set counter value to 0x7F, WWDG timeout = ~4 ms * 64 = 262 ms
WWDG_ClearFlag(); // Clear EWI flag
WWDG_EnableIT(); // Enable EW interrupt
}
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/* Setup the microcontroller system. Initialize the Embedded Flash Interface,
initialize the PLL and update the SystemFrequency variable. */
SystemInit();
/* Initialize LED1 and Key Button mounted on STM3210X-EVAL board */
STM_EVAL_LEDInit(LED1);
STM_EVAL_LEDInit(LED2);
STM_EVAL_PBInit(Button_KEY, Mode_EXTI);
/* Check if the system has resumed from WWDG reset */
if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET)
{
/* WWDGRST flag set */
/* Turn on LED1 */
STM_EVAL_LEDOn(LED1);
/* Clear reset flags */
RCC_ClearFlag();
}
else
{
/* WWDGRST flag is not set */
/* Turn off LED1 */
STM_EVAL_LEDOff(LED1);
}
/* NVIC configuration */
NVIC_Configuration();
/* WWDG configuration */
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/* WWDG clock counter = (PCLK1/4096)/8 = 1099 Hz (~910 µs) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 65 */
WWDG_SetWindowValue(65);
/* Enable WWDG and set counter value to 127, WWDG timeout = ~910 µs * 64 = 58.25 ms */
WWDG_Enable(127);
/* Clear EWI flag */
WWDG_ClearFlag();
/* Enable EW interrupt */
WWDG_EnableIT();
while (1)
{
}
}
/*******************************************************************************
* Function Name : main
* Description : Main program.
* Input : None
* Output : None
* Return : None
*******************************************************************************/
int main(void)
{
#ifdef DEBUG
debug();
#endif
/* System Clocks Configuration */
RCC_Configuration();
/* GPIO configuration */
GPIO_Configuration();
/* Check if the system has resumed from WWDG reset */
if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET)
{ /* WWDGRST flag set */
/* Set GPIO_LED pin 6 */
GPIO_SetBits(GPIO_LED, GPIO_Pin_6);
/* Clear reset flags */
RCC_ClearFlag();
}
else
{ /* WWDGRST flag is not set */
/* Reset GPIO_LED pin 6 */
GPIO_ResetBits(GPIO_LED, GPIO_Pin_6);
}
/* Configure Key Button EXTI Line to generate an interrupt on falling edge */
EXTI_Configuration();
/* NVIC configuration */
NVIC_Configuration();
/* WWDG configuration */
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/* WWDG clock counter = (PCLK1/4096)/8 = 244 Hz (~4 ms) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 65 */
WWDG_SetWindowValue(65);
/* Enable WWDG and set counter value to 127, WWDG timeout = ~4 ms * 64 = 262 ms */
WWDG_Enable(127);
/* Clear EWI flag */
WWDG_ClearFlag();
/* Enable EW interrupt */
WWDG_EnableIT();
while (1)
{}
}
static void s_hal_watchdog_window_start(hal_watchdog_internal_item_t *intitem)
{
// NVIC_InitTypeDef NVIC_InitStructure;
// do something using s_hal_watchdog_theinternals.items[0].countdown etc.
// acemor on 21oct11: taken from STM32F10x_StdPeriph_Lib_V3.2.0\Project\STM32F10x_StdPeriph_Examples\WWDG
// // 1. init nvic
// /* 1 bits for pre-emption priority and 3 bits for subpriority */
//// NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
//
//// NVIC_SetPriority(EXTI9_5_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),0,0));
//
// /* Set WWDG interrupt vector Preemption Priority to 1 */
// NVIC_InitStructure.NVIC_IRQChannel = WWDG_IRQn;
// NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
// NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
// NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
// NVIC_Init(&NVIC_InitStructure);
// 1b. wwdg clock
/* WWDG configuration */
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
// 2. set prescaler
/* On other devices, WWDG clock counter = (PCLK1(36MHz)/4096)/8 = 1099 Hz (909.918 us) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
// 3. set window
/* Set Window value to 65 */
WWDG_SetWindowValue(intitem->reload);
//WWDG_SetWindowValue(65);
// 4. set counter value and clear
/* On Value line devices, Enable WWDG and set counter value to 127, WWDG timeout = ~1366 æs * 64 = 87.42 ms */
/* On other devices, Enable WWDG and set counter value to 127, WWDG timeout = ~910 æs * 64 = 58.25 ms */
WWDG_Enable(intitem->reload);
/* Clear EWI flag */
WWDG_ClearFlag();
// 5. enable interrupt
if(hal_int_priorityNONE != intitem->cfg.priority)
{
// enable irqs in nvic
hal_sys_irqn_priority_set(WWDG_IRQn, intitem->cfg.priority);
hal_sys_irqn_enable(WWDG_IRQn);
/* Enable EW interrupt */
WWDG_EnableIT();
}
}
/**
* @brief 初始化窗口看门狗
* @param tr :T[6:0],计数器值 , wr :W[6:0],窗口值
@param fprer:分频系数（WDGTB）,仅最低2位有效 , Fwwdg=PCLK1/(4096*2^fprer).
* @retval None
*/
void WWDG_Init(u8 tr, u8 wr, u32 fprer)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE); // WWDG时钟使能
WWDG_CNT = tr & WWDG_CNT; //初始化WWDG_CNT.
WWDG_SetPrescaler(fprer);////设置IWDG预分频值
WWDG_SetWindowValue(wr);//设置窗口值
WWDG_Enable(WWDG_CNT); //使能看门狗 , 设置 counter .
WWDG_ClearFlag();//清除提前唤醒中断标志位
WWDG_NVIC_Init();//初始化窗口看门狗 NVIC
WWDG_EnableIT(); //开启窗口看门狗中断
}
/*
*********************************************************************************************************
* 函 数 名: bsp_InitWwdg
* 功能说明: 窗口看门狗配置
* 形 参：
* _ucTreg : T[6:0],计数器值 范围0x40 到 0x7F
* _ucWreg : W[6:0],窗口值 必须小于 0x80
* WWDG_Prescaler : 窗口看门狗分频 PCLK1 = 42MHz
* WWDG_Prescaler_1: WWDG counter clock = (PCLK1/4096)/1
* WWDG_Prescaler_2: WWDG counter clock = (PCLK1/4096)/2
* WWDG_Prescaler_4: WWDG counter clock = (PCLK1/4096)/4
* WWDG_Prescaler_8: WWDG counter clock = (PCLK1/4096)/8
* 返 回 值: 无
*********************************************************************************************************
*/
void bsp_InitWwdg(uint8_t _ucTreg, uint8_t _ucWreg, uint32_t WWDG_Prescaler)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* 检测系统是否从窗口看门狗复位中恢复 */
if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET)
{
/* 清除复位标志 */
RCC_ClearFlag();
}
else
{
/* WWDGRST 标志没有设置 */
}
/* 使能WWDG时钟 */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/*
窗口看门狗分频设置：
比如选择WWDG_Prescaler_8
(PCLK1 (42MHz)/4096)/8 = 1281 Hz (~780 us)
*/
WWDG_SetPrescaler(WWDG_Prescaler);
/*
设置窗口值是_ucWreg，用户必须在小于_ucWreg且大于0x40时刷新计数
器，要不会造成系统复位。
*/
WWDG_SetWindowValue(_ucWreg);
/*
使能WWDG，设置计数器
比如设置_ucTreg=127 8分频时，那么溢出时间就是= ~780 us * 64 = 49.92 ms
窗口看门狗的刷新时间段是: ~780 * (127-80) = 36.6ms < 刷新窗口看门狗 < ~780 * 64 = 49.9ms
*/
WWDG_Enable(_ucTreg);
/* 清除EWI中断标志 */
WWDG_ClearFlag();
/* 使能EW中断 */
WWDG_EnableIT();
/* 设置 WWDG 的NVIC */
NVIC_InitStructure.NVIC_IRQChannel = WWDG_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**
* @brief WWDG configuration
* @param None
* @retval None
*/
static void WWDG_Config(void)
{
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/* WWDG clock counter = (PCLK1 (48MHz)/4096)/8 = 1464Hz (~683 us) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 80; WWDG counter should be refreshed only when the counter
is below 80 (and greater than 64) otherwise a reset will be generated */
WWDG_SetWindowValue(80);
/* Enable WWDG and set counter value to 127, WWDG timeout = ~683 us * 64 = 43.7 ms
In this case the refresh window is: ~683 * (127-80)= 32.1ms < refresh window < ~683 * 64 = 43.7ms
*/
WWDG_Enable(127);
}
//初始化窗口看门狗
//tr :T[6:0],计数器值
//wr :W[6:0],窗口值
//fprer:分频系数（WDGTB）,仅最低2位有效
//Fwwdg=PCLK1/(4096*2^fprer). 一般PCLK1=42Mhz
void WWDG_Init(u8 tr,u8 wr,u32 fprer)
{
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG,ENABLE); //使能窗口看门狗时钟
WWDG_CNT=tr&WWDG_CNT; //初始化WWDG_CNT.
WWDG_SetPrescaler(fprer); //设置分频值
WWDG_SetWindowValue(wr); //设置窗口值
WWDG_Enable(WWDG_CNT); //开启看门狗
NVIC_InitStructure.NVIC_IRQChannel=WWDG_IRQn; //窗口看门狗中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x03; //抢占优先级为2
NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级为3
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE; //使能窗口看门狗
NVIC_Init(&NVIC_InitStructure);
WWDG_ClearFlag();//清除提前唤醒中断标志位
WWDG_EnableIT();//开启提前唤醒中断
}
void Wwdg_ExterslReloadReset_test(void)
{
unsigned short value = 0;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
uart_printf("RCC->CSR=0x%x\r\n",RCC->CSR);
uart_printf("WWDG->CR=0x%x\r\n",WWDG->CR);
uart_printf("WWDG->CFR=0x%x\r\n",WWDG->CFR);
uart_printf("WWDG->SR=0x%x\r\n",WWDG->SR);
uart_printf("IWDG->PR=0x%x\r\n",IWDG->PR);
uart_printf("IWDG->RLR=0x%x\r\n",IWDG->RLR);
uart_printf("IWDG->SR=0x%x\r\n",IWDG->SR);
WWDG_Enable(0x66);
WWDG_SetWindowValue(0x77);
value = WWDG->CR;
uart_printf("WWDG->CR=0x%x\r\n",WWDG->CR);
uart_printf("RCC1->CSR=0x%x\r\n",RCC->CSR);
uart_printf("RCC2->CSR=0x%x\r\n",RCC->CSR);
}
/**
* @brief Main program.
* @param None
* @retval None
*/
void WWDG_Example(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f30x.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f30x.c file
*/
/* Initialize LEDs and Key Button mounted on STM32303C-EVAL board */
STM_EVAL_LEDInit(LED1);
STM_EVAL_LEDInit(LED2);
STM_EVAL_PBInit(BUTTON_KEY, BUTTON_MODE_EXTI);
/* Check if the system has resumed from WWDG reset */
if (RCC_GetFlagStatus(RCC_FLAG_WWDGRST) != RESET)
{
/* WWDGRST flag set */
/* Turn on LED1 */
STM_EVAL_LEDOn(LED1);
/* Clear reset flags */
RCC_ClearFlag();
}
else
{
/* WWDGRST flag is not set */
/* Turn off LED1 */
STM_EVAL_LEDOff(LED1);
}
/* Setup SysTick Timer for 1 msec interrupts */
if (SysTick_Config(SystemCoreClock / 1000))
{
/* Capture error */
while (1)
{}
}
/* WWDG configuration */
/* Enable WWDG clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
/* WWDG clock counter = (PCLK1 (36MHz)/4096)/8 = 1098Hz (~910 us) */
WWDG_SetPrescaler(WWDG_Prescaler_8);
/* Set Window value to 80; WWDG counter should be refreshed only when the counter
is below 80 (and greater than 64) otherwise a reset will be generated */
WWDG_SetWindowValue(80);
/* Enable WWDG and set counter value to 127, WWDG timeout = ~910 us * 64 = 58.24 ms
In this case the refresh window is: ~910 * (127-80) = 42.7ms < refresh window < ~910 * 64 = 58.2ms
*/
WWDG_Enable(127);
while (1)
{
/* Toggle LED2 */
STM_EVAL_LEDToggle(LED2);
/* Insert 43 ms delay */
Delay(43);
/* Update WWDG counter */
WWDG_SetCounter(127);
}
}
void WWDG_init(void) {
RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);
WWDG_SetPrescaler(WWDG_Prescaler_8); /* WWDG clock counter = (PCLK1/4096)/8 = 244 Hz (~4 ms) */
WWDG_SetWindowValue(0x41);
WWDG_Enable(0x7F); /* Enable WWDG and set counter value to 0x7F, WWDG timeout = ~4 ms * 64 = 262 ms */
}