I'm Taro and I'm learning about clock products.
This time, I have a question about Real Time Clocks.
The frequency of the oscillator used in a clock is usually 32.768 kHz.
Why such a half-way frequency?
The 32.768 kHz frequency is not used as is, but is divided and used at a lower frequency.
32.768 kHz can be divided 15 times to make exactly one second.
However, we thought that if we wanted to make exactly one second, we could prepare a 16.384 kHz oscillator, which is half of 32.768 kHz, and save the time and effort of dividing the frequency.
Here, 32768 is expressed in binary,
When the most significant bit of a 16-bit counter is set to 1, it becomes 1 second.
In electronic circuits, this is more convenient than 16.384 kHz, since it is managed in 8 bit, 16 bit, 32 bit, etc.
Some Real Time Clock products can be programmed not only at 32.768 kHz, but also at 4096 Hz / 8192 Hz using an I2C interface, etc. Real Time Clock products are not limited to 32.768 kHz.
So, even though there are many different types of "Real Time Clocks," there are many different types that can be used depending on the design. Clock products are very deep!
For these reasons, 32.768 kHz is the best frequency for a Real Time Clock. 32.768 kHz is not a half way frequency!
I blush & I am convinced.
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