Thanks guys.
That is all fascinating! So it sounds like I may have been barking up the wrong tree with the CMSIS in the first place.
It seems that there is a pretty wide difference between what the SAM chip is capable of and the functions that are easily available through the standard Arduino and other available libraries. What I am really after is a way to get access to those cool SAM capabilities.
Sounds like ASM is the way to go for that. Perhaps I ought to start a new thread asking about how to get started with ASM?
Thanks.
Bill