Teledyne LeCroy USBTracer_Trainer - Users Manual - Manual (Page 24)

Chapter 1: Overview USB Protocol Suite User Manual
10
LeCroy Corporation
1.2.4 Traffic Generation
USB 2.0 and 3.0 traffic generation options allow you to transmit custom packets over
standard USB cables with low-level control of headers, payloads, timing, and link states.
The Exerciser can play back trace files bit-for-bit, allowing validation engineers to
recreate problems reported in the field or test-specific functionality.
To build generation script files, you can edit example test scenarios or export any traffic
stream from a previously recorded trace. The Voyager Exerciser includes a
Generation Script Editor.
A script pre-processor allows you to organize script code and create reusable generation
blocks.
For USB 3.0 applications, test scenarios can contain multi-stage traffic generation blocks
that include Boolean expressions, LOOP, DO-CASE, and IF-THEN logical branching.
The Voyager USB 2.0 Exerciser can transmit low, full, or high-speed traffic and supports
both host and device emulation. It is backward compatible with existing USBTrainer
traffic generation scripts.
For USB 2.0 applications, the Exerciser supports both bitstream mode or Intelliframe
mode. In Intelliframe mode, the Exerciser can wait for the appropriate response from the
DUT before transmitting the next packet. For example, after issuing an IN, the generator
waits for the DATAx packet returned by the device to finish, and then issues an ACK.
When NAKs are received, the Exerciser can automatically resend the previous packet.
Voyager ReadyLink™ Emulation
The LeCroy Voyager USB 3.0 Exerciser features ReadyLink Emulation Mode. The
ReadyLink feature handles all USB 3.0 link training and link flow control, allowing the
emulator to operate at full line rate and respond to the DUT as defined by the
specification. The ReadyLink Emulation Mode helps simplify development of USB 3.0
test scenarios.
By default, ReadyLink Emulation Mode automatically manages:
• Header Packet Acknowledgements (L_GOOD_n)
• Buffer Credit (L_CRD_x)
• SKIPs at required intervals (SKP)
• Link Synchronization
• Responds to LFPS (Polling.LFPS)
• Responds to polling sequence (Polling.RxEQ)
• Responds to TS1 / TS2 handshaking sequence
• Responds to SS.Inactive (with RX.Detect)
• Power Management Link Commands
• Responds to LGO_Un (with LAU)
• Responds to LAU (with LMPA)