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Comparing External Interrupts

Question asked by Thomas Olenik on Mar 25, 2016
Latest reply on Mar 27, 2016 by jeremyzhou

I'm working on a project using the KEA128 where I need to read a shaft encoder. Using the FRDM-KEA128 board, I'm successfully measuring the time between edges of the signal using the PWT, but I also want to count them. If I'm reading the documentation correctly, there seem to be several ways to trigger an external interrupt with the KEA128 to increment this counter. In order of priority these are:






The NMI is the highest priority, but it is only active low.

IRQ is the next highest priority, and it can be configured to detect rising or falling edges as well as levels.

ACMP is next in priority, and it can be used to trigger on a voltage level.

The KBI is the lowest priority of these options but it can read multiple inputs which are stored in the KBIx_SP register.


Did I miss any differences? It seems like the IRQ is the one I'm looking for, but wanted to see if there were other ideas out there.


Thanks ahead of time for any additional info.