I used this once to precisely derive one-second clock signal from system clock on a MCU. Usually you use 32.768kHz crystal because it divides nicely to 1 Hz. I

I used this once to precisely derive one-second clock signal from system clock on a MCU. Usually you use 32.768kHz crystal because it divides nicely to 1 Hz. I did not have it available and needed to use sytem clock that was not very precise nor a power of 2.