USB Advisor

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

The USB Advisor™ is LeCroy's ground-breaking All-Speed capable, USB Bus and Protocol Analyzer System. The industry's first USB 2.0 compliant analyzer, LeCroy's Advisor offers the powerful features that customers have come to expect from the undisputed leader in USB test and verification tools. It utilizes the de-facto standard CATC Trace software to capture, view and process USB traffic. It provides advanced multi-level triggering, sophisticated viewing and intelligent searching to accurately and efficiently debug and test High (480Mbps), Full (12Mbps) and Low speed (1.5Mbps) USB devices, software, and systems.

• CATC Trace Analysis Software System - Faster interpretation and debug of USB traffic
• 128 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, Bluetooth HCI, Hub, PTP/Still Image, Printer, PictBridge, Media Transfer Protocol (MTP), SCSI Mass Storage, Bluetooth HCI, Human Interface Devices (HID), Cable Based Association Framework, Audio, Communication, Host and Device Wire Adapter.
• 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
• Two Recording Channels - Both Classic and high-speed recording channels operate simultaneously making it useful for monitoring hub traffic
• Detach Device - Operates with the Classic recording channel and automatically disconnect and re-connect the link
• 3 Year Hardware Warranty - Protect your investment with industry leading warranty

Offering a unique combination of power and portability, the Advisor is LeCroy's 4th generation analyzer platform that is equally suited for field or lab environments. The Advisor offers 128MB of physical data recording memory, two recording channels, and a full-speed USB connection to the host PC. The high-speed recording channel is used for monitoring high-speed links. A separate Classic speed recording channel is used to record full-, and low-speed traffic. The USB Advisor allows both Classic and high-speed recording channels to operate simultaneously making it useful for monitoring both upstream and downstream traffic across a hub device.

Like other LeCroy tools, the USB Advisor 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, the USB Advisor preserves real-world signaling and provides 100% faithful representation of traffic on the bus.

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 packet 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 USB Advisor’s dual recording channels to simultaneously capture traffic from two USB branches, the software will automatically interleave packets from a single high speed link and a separate classic speed link in a unified display.

USB Advisor 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 Advanced 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 USB Advisor 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.