Part Number: MSP432P4111
Since the MSP432P4111 does not provide a battery backup for the real time clock I am adding an external RTC chip (I2C) with a battery backup to allow my codt to poll it for the time on power-up. The chip is a EPSON RX8804CE and has better stability specifications than the MSP 430. The chip also has a 32.768kHz output.
What I would like to know is (1) can I drive the LFXIN pin on the MSP with the output of the RX8804 or does it HAVE to be a crystal? What do I do with the LFXOUT pin? (2) Due to the necessity of Diode-ORING the backup battery with VCC on the board, the level of the 32.768 kHz signal coming from the RTC chip will be one (schottky) diode drop lower than VCC. Will that be a problem?
Thank you.
Paul Mayer