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Using crystal instead of clock generator with K60F120M

Question asked by Angelo Quattrociocchi on Sep 15, 2014
Latest reply on Sep 27, 2014 by Kan_Li

I have a custom board based on the K60F120M tower board, which has an clock generator on XTAL0/EXTAL0, and a crystal on XTAL1/EXTAL1.  I left off the external clock, and have only the crystal, but unfortunately I left it on XTAL1/EXTAL1, and now it seems like that won't work.


But when I change to use XTAL0/EXTAL0, the basic tower board demo projects don't run anyway.


1. Is it possible to run the device off a crystal on XTAL1/EXTAL1 pins only?  From reviewing the reference manual, it looks like XTAL1/EXTAL1 can only drive some peripherals, and not all internal clocks.  Is this right?


2. Assuming I move the crystal to the XTAL0/EXTAL0 pins, is there some clock configuration change I need to make to work off the crystal as opposed to a clock input?  I noticed some settings such as gain, etc., but I tried various things and couldn't get it starting.  It stalls in __pe_initialize_hardware of bsp_cm.c in a while loop waiting for a required clock condition.