USBSpy provides a complex solution in the sphere of USB communications.
Edit by : USBSpy provides a complex solution in the Sphere of USB communications. Its area of application spans from studying USB topology to developing protocols. Here are some application areas where you can benefit from it:

Developing and Debugging Device Drivers
When you develop a driver for a custom USB device, it is always useful to study I/O requests. USBSpy lets you choose any device registered in the host system and monitor its transactions with the root hub. The range of supported requests includes configuration, setup, data requests, and power management. Using the programs triggering options, it is easy to Detect software, driver, and firmware problems. You can trigger on a variety of conditions including packet types, device requests, completion statuses, errors and many others. Triggers can be set up on almost any events. The support for hot-plugged devices allows recording requests right from the enumeration dialogue.
Debugging USB-bound Applications
Support for URB structures and PRECISE timing can be effectively used to debug applications programs that work with USB devices. Although USBSpy records all traffic of the selected device, you can apply filters to narrow down the view to just those packets that contain relevant communications. This is especially useful when devices with complex traffic are attached.
Debugging Firmware
Firmware is at the core of the exchange of data requests Between device endpoints and the real world. With USBSpy you can peel back the layers of a custom USB device to get close to the data sent and received at its endpoints. This will show how adequate the firmware performance is.
Solving Compatibility Issues
Before new hardware or software can be implemented, administrators often run it through series of tests to make sure it can perform adequately. USBSpy provides the required testing environment when USB solutions are checked for compatibility.
Studying USB Communications you can free download USB Spy 2.0 now.