When starting to use the Snickerdoodle for the first time, some of the Zynq pin names can be confusing.
There are a few resources you should be looking at when referencing pin-outs for the Zynq chip on your Snickerdoodle.
ug865 User Guide
Xilinx provides a variety of "ug" user guide documents for their products. The ug865 ("Zynq-7000 SoC Packaging and Pinout Product Specification") (2018-07 version) in particular can be useful when trying to understand the pins of the Zynq-7010 or Zynq-7020 -clg400's on Snickerdoodle boards.
Especially of interest is the "ASCII Pinout Files" section. There you should find a link to the ASCII file for the Zynq chip on your Snickerdoodle board.
Additionally the "Pin Definitions" section will also be helpful.
TODO: rewrite and review the rest of this document