Hi All
Newer and larger KL parts have something called an Interrupt multiplexer (INTMUX) which is used to extend the Cortex-M0+ NVIC limit of 32 peripheral interrupt to accommodate a larger set of peripheral interrupts.
The following video explains the details, code required to use it and demonstrates the RTC Alarm interrupt (extended peripheral interrupt) on the KL82 (FRDM-KL82Z): https://youtu.be/zKa5BoOhBrg
The binary of the code used in the video is available at http://www.utasker.com/kinetis/FRDM-KL82Z.html#INTMUX
and also shows running a dual OS on the board (uTasker + FreeRTOS).
Regards
Mark