忙里偷闲学习ufun_16]窗口看门狗——WWDG_Reset

boming

窗口看门狗和其它看门狗不一样的地方。喂狗过早，狗也会咬人。过晚更咬人。这点一直不知道，调试很久才知道
/* WWDG configuration */
  /* Enable WWDG clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE);

/*  WWDG clock counter = (PCLK1(72MHz)/4096)/8 = 2197 Hz (~455 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 1) otherwise a reset will be generated */
  WWDG_SetWindowValue(126);

  /*
    Enable WWDG and set counter value to 126, WWDG timeout = ~455 us * 1 = 455 us
    In this case the refresh window is: ~455 us * (127-126) = 455 us  < refresh window < ~455us * 64 = 2.912ms     
  */
  WWDG_Enable(127);
  while (1)
  {

printf("\r\n 看门狗吃东西中。。! \r\n");

    /* Update WWDG counter */
    WWDG_SetCounter(127);
  }
}
窗口看门狗.rar (245.86 KB, 下载次数: 2)

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kangkls

窗口看门狗不能一个劲的喂。
The Configuration register (WWDG_CFR) contains the high limit of the window: To
prevent a reset, the downcounter must be reloaded when its value is lower than the
window register value and greater than 0x3F
参考手册图184