This file provides firmware functions to manage the following functionalities of the Window watchdog (WWDG) peripheral: More...
Go to the source code of this file.
|Clears Early Wakeup interrupt flag. More...|
|Deinitializes the WWDG peripheral registers to their default reset values. More...|
|void||WWDG_Enable (uint8_t Counter)|
|Enables WWDG and load the counter value. More...|
|Enables the WWDG Early Wakeup interrupt(EWI). More...|
|Checks whether the Early Wakeup interrupt flag is set or not. More...|
|void||WWDG_SetCounter (uint8_t Counter)|
|Sets the WWDG counter value. More...|
|void||WWDG_SetPrescaler (uint32_t WWDG_Prescaler)|
|Sets the WWDG Prescaler. More...|
|void||WWDG_SetWindowValue (uint8_t WindowValue)|
|Sets the WWDG window value. More...|
This file provides firmware functions to manage the following functionalities of the Window watchdog (WWDG) peripheral:
* ============================================================================== ##### WWDG features ##### ============================================================================== [..] Once enabled the WWDG generates a system reset on expiry of a programmed time period, unless the program refreshes the counter (downcounter) before to reach 0x3F value (i.e. a reset is generated when the counter value rolls over from 0x40 to 0x3F). [..] An MCU reset is also generated if the counter value is refreshed before the counter has reached the refresh window value. This implies that the counter must be refreshed in a limited window. [..] Once enabled the WWDG cannot be disabled except by a system reset. [..] WWDGRST flag in RCC_CSR register can be used to inform when a WWDG reset occurs. [..] The WWDG counter input clock is derived from the APB clock divided by a programmable prescaler. [..] WWDG counter clock = PCLK1 / Prescaler. [..] WWDG timeout = (WWDG counter clock) * (counter value). [..] Min-max timeout value @36MHz (PCLK1): ~114us / ~58.3ms. ##### How to use this driver ##### ============================================================================== [..] (#) Enable WWDG clock using RCC_APB1PeriphClockCmd(RCC_APB1Periph_WWDG, ENABLE) function. (#) Configure the WWDG prescaler using WWDG_SetPrescaler() function. (#) Configure the WWDG refresh window using WWDG_SetWindowValue() function. (#) Set the WWDG counter value and start it using WWDG_Enable() function. When the WWDG is enabled the counter value should be configured to a value greater than 0x40 to prevent generating an immediate reset. (#) Optionally you can enable the Early wakeup interrupt which is generated when the counter reach 0x40. Once enabled this interrupt cannot be disabled except by a system reset. (#) Then the application program must refresh the WWDG counter at regular intervals during normal operation to prevent an MCU reset, using WWDG_SetCounter() function. This operation must occur only when the counter value is lower than the refresh window value, programmed using WWDG_SetWindowValue().
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Definition in file stm32f30x_wwdg.c.