Copy of ASF (Atmel Software Framework) excerpts for the SAMD21 processor used in the Arduino Zero / Adafruit Feather M0 boards. You typically won't use this library directly, instead other libraries will depend on this library and use the code within it to simplify their implementation.
All code is taken directly from Atmel's ASF: http://www.atmel.com/tools/avrsoftwareframework.aspx?tab=overview
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