This report is a circuit analysis of the USB 2.0 I/O block within the Terminus Technology FE1.1s USB 2.0 4-port hub controller. Analog portions of the I/O circuits for DPU and DMU pads are analyzed. This report contains the following information: a partial set of schematics with device size measurements, organized in a hierarchical manner, and accompanied by signal descriptions and cross references, a signal reference list summarizing all signal sources and destinations, package, X-ray, die markings, and die photographs, and a device summary.