USB 2.0 Traffic Generation allows you to generate USB 2.0 traffic and test designs under realistic conditions. Traffic Generation can also transmit known bad packets, providing an opportunity for engineers to observe how a device handles specific adverse conditions.
The 2.0 Generation scripts can create almost arbitrary streams of packets, but the responsibility for creating a sequence that performs in an expected way is left to the user. For example, if a Host Emulation script starts with just sending bulk data on an endpoint, no real device purchased in the store can react to it, as it expects to be enumerated and be in the correct state when the Bulk transfer begins. In the Device Emulation situation, it is expected that the device will supply all the correct enumeration responses, in the order expected by the host, for it to proceed to its normal behavior mode. Since different hosts may enumerate devices in slightly different orders, you may have to adjust the device emulation script file to match this. By creating the Host Emulation or Device Emulation script from the process of exporting from a real trace with a real Device or Host, the likelihood of starting out with a working script is increased enormously, since the behavior should be repeatable.
NOTE: For traffic generation for USB 3.2, see Traffic Generation USB 3.2, USB4, & PD Exerciser.