Updated: Sep 11, 2018
This post contains details about the ZCU102's USB-to-JTAG Digilent module, the circuit its used in, a picture of the components on the board and a diagram of the resultant JTAG chain.
The ZCU102 allows JTAG to be used over USB with a Digilent USB JTAG-to-USB module.
The module is available at [link].
Info from the ZCU102 BOM:
Reference designation on board: U21
Device: USB Module
Manufactured and distributed by Digilent
Manufacturer part number: JTAG-SMT2-NC
Distributor part number: 410-308P
JTAG_TDI, JTAG_TMS and JTAG_TCK also route to J6, U48 and the Zynq UltraScale+ MPSoC as seen at [link].
When used without FMC cards, the JTAG chain from the DIGILENT_USB_JTAG_2_NC looks like:
Diagram available at [link].
ZCU102 Layout (bug: see [link])
Allegro Viewer at [link] (needed to view layout files)