版本 e8fd1baedcb74c7fcc23e39c027487d8ec5d1eab
Changes from e8fd1baedcb74c7fcc23e39c027487d8ec5d1eab to ce8887a52780f5e46945c48dd05dd8ed52bae5c5
Introduction
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A real-time clock (RTC) is a computer clock that keeps track of the current time. RTCs are also present in almost any electronic device that requires accurate time keeping. The real-time clock (RTC) embedded in STM32 microcontrollers acts as an independent BCD timer/ counter.
Features
===============
- Calendar
- Alarm
- Auto wakeup
- Timestamp
- Tamper detection
- Programmable daylight saving time
- Didigal calibration
- Synchronization
- Reference clock detection
- Backup register
- Alternative function IO
Clock Source
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LSI RC : 32 kHz
LSE OSC : 32.768 kHz
HSE OSC : 4-26 MHz
.. image:: /stm32F4 RTC clock source
Prescaler
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Prescaler generates the clock to update update the calendar.
To minimize power comsuption the prescaler is split into two prescalers, asynchronous and synchronous. It is recommended to configure the asynchronous prescaler to a high value to minimize consumption.
asynchronous prescaler clocks subsecond of calendar and propagate to synchronous prescaler to update date and time by second.
Configuration
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