STM8L 的独立看门狗由内部专门的 38Khz 低速时钟驱动，即便主时钟产生毛病，它也依然有用。这儿需求留意独立看门狗的时钟并不是准确的 38Khz，仅仅咱们在预算的时分，以 38Khz 的频率来核算，看门狗对时刻的要求不是很准确，所以，时钟有些误差，都是能够承受的。依据分频体系和看门狗计数值能够设置独立看门狗的复位时刻，规模从0.1ms~1724.63ms
例程展现怎么重载IWDG计数值，IWDG的时刻设置为214.7ms。程序选用“Refresh”变量来使能IWDG重载计数值仿真IWDG复位，而且板上LED4翻转。当按键按下，模仿一次软件过错形成程序没有喂狗，然后产生复位。假如IWDG复位，体系启动后LED3会翻转8次，主代码如下：
void main(void)
{
uint8_t Index;
GPIO_Init(LED3_PORT,LED3_PIN,GPIO_Mode_Out_PP_Low_Fast);
//输出低电平-高速10M
GPIO_Init(LED4_PORT,LED4_PIN,GPIO_Mode_Out_PP_Low_Fast);
//输出低电平-高速10M
GPIO_Init(KEY_PORT,KEY_PIN,GPIO_Mode_In_FL_IT);
//输入浮空-中止
/* Set PC1 sensitivity to falling edge and low level 下降沿低电平触发*/
EXTI_SetPinSensitivity(EXTI_Pin_1, EXTI_Trigger_Falling_Low);
/* Check if the MCU has resumed from IWDG reset */
if (RST_GetFlagStatus(RST_FLAG_IWDGF) != RESET)
{
/* IWDGF flag set */
/* Toggle LED3 */
for (Index = 7; Index != 0; Index–)
{
GPIO_ToggleBits(LED3_PORT,LED3_PIN);
Delay(0x7FFF);
}
/* Clear IWDGF Flag */
RST_ClearFlag(RST_FLAG_IWDGF);
}
/* IWDG configuration: IWDG is clocked by LSI = 38KHz */
/* IWDG timeout equal to 214.7 ms (the timeout may varies due to LSI frequency dispersion) */
/* IWDG timeout = (RELOAD_VALUE + 1) * Prescaler / LSI = (254 + 1) * 32 / 38 000 = 214.7 ms */
/* Enable the IWDG */
IWDG_Enable();
/* Enable write access to IWDG_PR and IWDG_RLR registers */
IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
/* Set IWDG timeout */
IWDG_SetPrescaler(IWDG_Prescaler_32);
IWDG_SetReload(RELOAD_VALUE);
/* Refresh IWDG */
IWDG_ReloadCounter();
/* enable interrupts by switching to level 0 */
enableInterrupts();
while (1)
{
/* As Refresh is equal to ENABLE no IWDG reset will occur. When Refresh is
equal to DISABLE, the IWDG counter isnt refreshed and IWDG reset will occur. */
if (Refresh != 0)
{
/* Reload IWDG counter */
IWDG_ReloadCounter();
}
/* Toggle LED4 */
GPIO_ToggleBits(LED4_PORT,LED4_PIN);
Delay(0x6FFF);
}
}
