Teledyne LeCroy USB Protocol Suite User Manual (Voyager_Advisor T3_Mercury) - Manual (Page 327)

USB Protocol Suite User Manual 327
Starting Traffic Generation Teledyne LeCroy Corporation
 Bitstream Mode ‐ In Bitstream Mode, the generator constructs a bitstream of
traffic based on the UTG file and assumes that packets start at pre‐calculated
times. For example, after an IN packet, the generator waits a calculated fixed
time before presenting an ACK. The time between them is determined by the
idle= time statement in between the IN and ACK packets in the .utg file. In this
mode, every bit time of a generation stream (including idles and SE0's) is repre‐
sented by 4 bits of data, so the file to be downloaded to the Generator can be
very large.
 IntelliFrame Mode ‐ In IntelliFrame mode, the generator can wait for Device
responses to complete before it continues generating more host packets. For
example, after issuing an IN, the generator looks for the DATAx packet issued by
the device to finish, and then issues an ACK. This way, the data length can vary
and does not need to be pre‐calculated. Also, using the idle=TO_EOF statement
allows the generator to calculate where the end of the frame occurs, so that a
subsequent frame=AUTO statement creates a Start of Frame at the correct time.
Moreover, the Generator can be made to retry transactions that are NAKed auto‐
matically, and to use the PING protocol where appropriate. Retries can be made
to occur within the same frame or in the next frame. For further information on
the flexible behavior that can be instituted during the generation, see the syntax
descriptions for the generation files here. An additional advantage of the Intelli‐
Frame mode is that it creates an image in the Generator's memory that is MUCH
smaller than that of the Bitstream mode, so it downloads much faster.
Note:
Device emulation only works in Intelliframe mode.
Note:
In IntelliFrame mode, the hardware generates SOFs and Pings, so these cannot be altered (force
CRC value, explicit frame number, and so on). If you want to explicitly corrupt or manage these
PID types, you must use Bitstream mode.
11.7 Starting Traffic Generation
To start traffic generation, click on the Tool Bar.
11.8 Repeating a Generation Session
If you wish to repeat a generation session, press the Traffic Generation Start/
Stop
button again. There is no need to reload the .utg file.
You can make an additional entry in a Generator Text File that allows you to specify a
portion of the file for repetition:
 Enter wrap=here in the Generator Text File.
The traffic above the entry is run only once. The traffic below the entry is repeated
continuously.
Note: For a usage example, see the sample file FS_Enum_Break_Wrap_Sample.utg.