The WDCON is the EICON register, SFR at D8h. Please see the Technical Reference Manual (version 1.2) of the EZ-USB FX, chapter 2 for further details. The EICON was WDCON in DS80C320 ( Bit Values differ from Reg320). Make sure you are using the latest development tools. This has been updated in the framworks header files (ezusb.h and ezreg.c).