usb host - My USB D+ and D- signals have what looks like a clock signal embedded onto it. The chip is a ISP1362 - Electrical Engineering Stack Exchange
USBee QX 2.0 Mixed Signal Oscilloscope, Logic Analyzer, Signal Generator, Protocol Decoder and Analyzer
PC based USB Oscilloscope $129 up | Perytech
Understanding and Performing USB 2.0 Physical Layer Testing and Debugging