USBTracer/Trainer

USB, or Universal Serial Bus, is a connectivity standard that enables computer peripherals and consumer electronics to be connected to a computer without reconfiguring the system or opening the computer box to install interface cards. USB was introduced in 1995 and replaces the serial, parallel, mouse and keyboard ports. The host computer automatically recognizes the device and installs the appropriate drivers. It is a fast, bi-directional, low-cost, dynamically attachable serial interface that was visualized to provide ease of connectivity to PCs. With features such as high speed and hot "plug-ability", USB has become a de-facto standard for various consumer and PC peripheral devices. USB connectivity standard allows up to 127 devices connected to a Host System. The current standards of USB allow data transfer rates of 1.5 Mbps, 12 Mbps, 480 Mbps, and more recently 5Gbps. USB designates low, full, high-speed connectivity between devices compatible with the 2.0 specification. Most full speed devices include lower bandwidth mice, keyboards, printers, and joysticks.

USB emerged in late 1995 from the shortcomings of peripheral devices implementation. Shortly after its introduction, USB became widely popular and is now the most popular peripheral interconnect in history. USB continues to be dominant for the following reasons:

• Mature, proven technology
• Backward-compatible and low cost
• Easy plug and play operation
• Data transfer speeds suitable for a variety of applications

As evidenced by USB popularity, several extensions of the technology have been introduced to try and capitalize on its installed base/ popularity. An example of this extension, which is supported and approved by the USB Implementers Forum (USB-IF), is USB On-The-Go (OTG). In addition, several products that have traditionally been 1394-based such as digital camcorders are now coming to market with USB 2.0. Wireless USB has also emerged as the de facto standard for wireless personal area networking.

USB was initially introduced as a host to peripheral interconnect with the goal of putting most of the intelligence on the host-side. The OTG specification added an optional peer-to-peer capability to devices but had limited adoption to date. So the vast majority of USB devices typically fall into 2 categories:

• PCs, Macs and laptops

• All devices designed to attach to a host (examples)

The role of the host controller (plus software) is to provide a uniform view of IO system for all applications software. For the USB IO subsystem in particular, the host manages the dynamic attach and detach of peripherals. It automatically performs the enumeration stage of device initialization which involves communicating with the peripheral to discover the identity of a device driver that it should load, if not already loaded. It also provides device descriptor information that drivers can use enable specific features on the device. Peripherals add functionality to the host system or may be standalone embedded operation. When operating as a USB device, peripherals act are slaves that obey a defined protocol. They must react to requests sent from the host. It’s largely the role of PC software to manage device power without user interaction to minimize overall power consumption. The USB 3.0 specification redefines power management to occur at the hardware level with multiple power states designed to reduce power usage across the IO system.

• USB Implementer's Forum
• Intel
• Microsoft

Portions Copyrighted 2007, PCI Special Interest Group
Wikipedia contributors, "Peripheral Component Interconnect," Wikipedia, The Free Encyclopedia,

Invaluable in the development of USB silicon, firmware and software, LeCroy's flagship validation platform for USB is an integrated analyzer / exerciser system that allows design engineers to test functionality, error recovery and compliance for low, full and high-speed USB devices. Based upon the 2500H platform, the USBTracer/Trainer is available in both an analyzer / exerciser system or an analyzer only configuration. Both options are fully supported by the industry leading CATC Trace software, which simplifies analysis tasks with its hierarchical display of USB transactions.

• CATC Trace Analysis Software System - Faster interpretation and debug of USB traffic
• OTG (On-The-Go) Support - Record and analyze HNP & SRP, including the capture of VBus and Data line pulses
• Traffic Generation/Device Emulation - Fully integrated traffic generator for error injection, stress testing and validating device compliance.
• 512 MByte Recording Capacity - Capture long recording sessions for analysis and problem solving
• Non-intrusive High Impedance Probe - Ensures non-corrupted and uninterrupted data
• Advanced Triggering - Trigger and filter on both recording channels to easily isolate important traffic, specific errors or data patterns
• Extensive Decodes - Mass Storage, USB Attached SCSI (UAS), Hub, PTP/Still Image, Printer, PictBridge, Media Transfer Protocol (MTP), CDC, Bluetooth HCI, Human Interface Devices (HID) and more
• Real-Time Statistics - View bus traffic as it occurs even if a Trace is not being recorded
• Hardware Filtering - Automatically exclude non-essential and redundant packets from the trace
• Intelligent Reporting - Automatically report event metrics and flag over 20 common USB protocol errors
• Sophisticated Viewing - View Packet, Transaction and Transfer layers of the USB protocol
• Dual Recording Channels - Simultaneously record all USB speeds on both channels making it ideal for USB hub testing
• Hi-Speed USB Port - USB 2.0 Hi-Speed connection for quick uploading of Trace Data
• Reliable CATC™ 2500H Platform - Modular platform design allows for use with other LeCroy-supported technologies
• Bit-level traffic generation - Script-based control language allows precise packet and timing control - to the bit-level
• Host and device emulation modes – Mimic real traffic while recording actual device response
• Intelliframe™ mode – Exerciser automatically searches for the correct response from the device-under-test before transmitting the next packet
• 3 Year Hardware Warranty - Protect your investment with industry leading warranty

The USBTracer is a plug-in module that install into LeCroy's Universal Protocol Analyzer System (2500H). The USBTracer offers two recording channels that can record Hi-Speed, Full Speed and Low Speed USB traffic. USBTracer's modular design allows developers to start with the analyzer only configuration and add the exerciser option in the future by purchasing the USBTrainer generator module.

Like other LeCroy tools, USBTracer/Trainer boasts a high-impedance, non-intrusive probe that acts strictly as a "sniffer" and does not re-time or affect amplitude between the host and device. Completely passive in design, USBTracer/Trainer preserves real-world signaling and provides 100% faithful representation of traffic on the bus.

The heart of the USBTracer/Trainer Analyzer System is LeCroy's revolutionary BusEngine™ technology. This state-of-the-art protocol processing core incorporates a real-time recording engine and configurable tools to selectively monitor and record USB traffic. All BusEngine logic is fully field-upgradeable.

Other hardware features includes a Hi-Speed USB port for uploading recorded traffic to the host PC. This provides fast workflow by transferring data at up to 480Mbit per second. Software running on the PC is used to control the analyzer's recording options via the same USB port. Users can adjust the depth of the recording memory - up to 512 Mbytes - and determine where in the recording the trigger is located.

The USBTrainer is an add-on module to the USBTracer analyzer system. It transmits valid and invalid traffic over standard USB cables. Users create test patterns by exporting any traffic stream from a previously recorded USBTracer trace. These stimulus files can be played back bit-for-bit using LeCroy's USBTrainer module. This allows validation engineers to easily recreate problems reported in the field using a simple trace file.

A text-based API can also be used to create packet level traffic files. The ability to insert code errors, or customized data payloads makes it easy to perform corner-case, stress, and limit testing. Users have the freedom to insert errors anywhere within the stream to validate fault handling. The generator is capable of transmitting low, full, or high-speed traffic and combined root port USB message packets.

The LeCroy exerciser also offers Intelliframe mode which adds automatic wait states to the traffic stream. When enabled, the Intelliframe mode will intelligently 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 be set to automatically resend the previous packet. Used in conjunction with the LeCroy USBTracer™ analyzer module, the USBTrainer™ makes the LeCroy system the most flexible platform for USB development and compliance verification.

Featuring the highly intuitive CATC Trace™ expert analysis software, the LeCroy system trains the eye to understand more information faster. Packets are shown on separate rows with every field labeled and color coded. Errors are identified and highlighted in red. The USB Transfer level can be expanded and collapsed to show all three layers of the USB protocol: Packet, Transaction and Transfer. For more efficient and deeper analysis, users can view Block Transfers at each layer or the actual raw data bits recorded on the line.

The CATC Trace detects and alerts the user to every potential violation at all levels of the protocol layering, from running disparity to the proper sequencing of the handshaking. The proper formation of each command is checked for validity and compliance to the specification, including the recalculation and checking of CRCs. It also supports vendor specific decoding for developers interested in automatically showing proprietary commands in the trace view. When using USBTracer's dual recording channels to simultaneously capture traffic from two USB branches, the software will automatically interleave packets from both links in a time correlated display.

The USBTracer offers full support for the OTG specification. The analyzer identifies both the HNP(Host Negotiation Protocol) and SRP (Session Request Protocol) occurrences. VBus and Data Line pulses are captured, displayed and integrated in the trace file. This synchronized view of the OTG protocol provides users with a complete, end-to-end look at OTG occurrences on the bus. Additional application layer decoding includes Mass Storage, USB Attached SCSI (UAS), Hub, PTP/Still Image, Printer, PictBridge, Media Transfer Protocol (MTP), CDC, Bluetooth HCI, Human Interface Devices (HID), plus Link Power Management (LPM) signals.

USBTracer/Trainer provides many mechanisms to measure and report on USB traffic. The Bus Utilization graphs data and packet length, bus usage by device other statistical data. The Bandwidth calculator automatically calculates the time delta between two points in the trace.

Using the Traffic Summary window, users can evaluate statistical reports at a glance or navigate to individual fields. A user may select Tokens, Data or Handshake at the Packet level, Handshakes at the Transaction level, and Control at the Transfer level, then jump to each occurrence with a single keystroke. Error events are also included in the summary reports.

Powerful Search and Find options allow users to quickly navigate to specific packets, errors and any data type within a trace file. The CATC Trace supports filter and hide commands, to remove irrelevant data from the Trace for efficient viewing.

For efficient development of USB systems, an analyzer has to let users extract useful information from a crowded stream of traffic, and accurately identify and selectively record what interests them most. The USBTracer Analyzer offers hardware triggering to capture real-time events and on-the-fly filtering to preserve memory and pinpoint data of interest. Additionally, with its comprehensive error detection and analysis, users can easily trigger on protocol, CRC or PID errors.

LeCroy's recording options provide a graphical drag-and-drop interface that makes multilevel triggering easy. Users can specify up to seven levels of event sequencing and counting with each event tracking a particular activity. For example: "trigger on the fifth occurrence of a SETUP Token device number nine", or "trigger on a SET INTERFACE request, following a specified eight-byte bulk data pattern match from this specific DUT while filtering out start-of-frame (SOF) packets."

LeCroy's USBTracer has a well earned reputation as the most accurate and reliable protocol analyzer available. Combined with the USBTrainer exerciser option and the CATC Trace expert analysis software, the LeCroy system really is the "all-in-one" solution for USB test and validation.