AnsweredAssumed Answered

MK66 custom board, using USB1, no PLL lock

Question asked by Herwin Grobben on May 23, 2017
Latest reply on May 23, 2017 by Mark Butcher

I'm developing an application which uses the High speed USB in device mode from the Kinetis 66. I based my code on the CDC + MSC lite example code from the MCUXpresso SDK.


I got it to build in our custom environment (after removing the MSC part, I don't need it). But the processor gets stuck in the APPInit, when it is checking for the USBPHY PLL to lock (function bool CLOCK_EnableUsbhs0PhyPllClock(clock_usb_phy_src_t src, uint32_t freq)).


I've found several topics covering the issue, and walked through them:

- we use the xtal mode, not extosc, so no ERRATA_ID_9712 dependency (

- correct xtal (16 MHz)

- I have a correct voltage on USB VREG pin (3v3) delivered from VREG_IN1 and VREG_IN0

- all assert() statements in the beginning of the function checked out correctly

-- 32k is running 


I didn't check any runmode in previous init routines, but can they interfere with the settings introduced in this function, stopping the PLL to lock?


Please advice.