The DS3231 is an RTC chip with an onboard temperature compensated oscillator and 32kHz output.
I want to use this chip in a small clock project I'm designing because I've got a couple lying around. Since it's got the the 32kHz output, I want to use that as a main clock source for the microcontroller (PIC18F4550) and skip the discrete XTAL to save on space and BOM.
All the examples I have found use a higher-speed crystal to drive the main microcontroller and ignore the 32kHz output of the RTC, although sometimes the 32kHz is used to drive other circuitry.
This is making me doubt my design decision, but I haven't found anything that outright says I can't do it. Are there any gotchas I should know about before I fab the board? I realize that by using this method I don't have a second clock source to tune the oscillator. I do plan on prototyping it.
Here is my schematic:
(The TPS chip is a 3.3V regulator connected right up to the 9V battery. EN should read /EN)