Teledyne LeCroy USB Protocol Suite User Manual (Voyager_Advisor T3_Mercury) - Manual (Page 315)

USB Protocol Suite User Manual 315
Chapter 11
Traffic Generation 2.0
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 which 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 it's 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 3.0, see “Traffic Generation 3.0 Exerciser” on page 349 .
11.1 Connecting to Voyager M3/M3i
The connections differ for Host Emulation and Device Emulation.
Full Speed, Low Speed, and Hi Speed connections are the same.
Hi/Full/Low Speed Host Emulation
For Host Emulation Hi, Full, or Low Speed, connect to the Voyager M3/M3i according to
the following diagram (see
Figure 11.1 on page 316 .).