I read the "Reference Design User Manual for AP2Dk1 and ANTDKT3"
(http://www.thisisant.com/images/stories/PDF/ant dkt reference design user manual.pdf)
but it seems that the topic for interfacing with C17 MCU is not in this document.
The reference code you are referring to was designed for the Epson SVT17705 development kit, and is distributed by Epson. You can get the reference code, along with other development resources on their website (I believe registration is required) http://www.epson.jp/device/semicon_e/product/mcu/16bit/