Link Trainer Exercises PCI Express Gen2 Devices

The Gen2 PCI Express LinkUP Trainer from LeCroy Corp. is the companion development tool for the PCI Express PETracer Gen2 Summit Analyzer, which began shipping in August. The device is a card-based exerciser (see the Figure) for a link training and status state machine (LTSSM). It can generate training sequences at Gen1 and Gen2 speeds for lane widths from x1 to x16. As such, the LinkUP exerciser is very useful for designers who are developing PCI Express Gen2 products and need a controllable host or device running at 5-Gbit/s speeds.

LinkUP allows users to test their products to find potential issues that can affect interoperability. Features such as the LTSSM emulator generate protocol traffic to a device or host. The system can be configured to transition to various states, and to change speeds to test speed negotiation. ACKs are also generated for received Transaction-Layer Packets (TLPs) to emulate the Data Link Layer and preserve the link. In addition, each PCI Express lane's parameters such as lane skew, polarity, and scrambling can be changed to expose physical layer issues.