In many projects over the past years, I used several versions of the Atmel/Microchip AT32UC3C series. In that time a framework with hardware functions was created. Like the Atmel ASF, which had no support for the AT32 series.
The whole framework is published on github: https://github.com/Wardstein/Atmel-UC3C-Framework
Please feel free to contact me and pull requests are welcome, too :-)
Image Source: Microchip AT32UC3C-EK (https://www.microchip.com/en-us/development-tool/AT32UC3C-EK)