SATA Avalanche

• Performance - Parallel ATA does not have scalability to support several more speed doublings, and it is nearing its performance capacity. By contrast, Serial ATA defines a roadmap starting at 1.5 gigabits per second (equivalent to a data rate of 150 MB/s) up to 6Gigabits per second.
• Lower Voltage - Parallel ATA's 5-volt signaling requirement will be increasingly difficult to meet as the industry continues to reduce chip core voltages. Serial ATA is better aligned with future manufacturing processes. It reduces signaling voltages to approximately 250 millivolts (1/4 volt).
• Pin Count - Currently, the parallel ATA interface has 26 signal pins going into the interface chip. Serial ATA uses only 4 signal pins, improving the pin efficiency and accommodating a highly integrated chip implementation.
• Improved Cabling - Parallel ATA bulky ribbon cables contain 40-pin header connector. Serial ATA introduces thin, flexible cabling scheme that offers longer cables and improved airflow within the chassis.
• Software Compatible - Serial ATA is compatible at the register level with parallel ATA. This means Serial ATA requires no changes to existing software and operating systems in order to function, and it provides backward compatibility with existing operating environments.
• SAS Compatibility - A significant feature offered by Serial ATA is the expectation that SATA will be form-factor compatibility with Serial Attached SCSI. SATA drives will plug directly into Serial Attached SCSI connectors and if supported in the system, will transparently operate as a SATA device. This allows systems to be deployed that can use either Serial Attached SCSI drives, for their high performance or SATA drives that will provide a lower-cost-per-megabyte storage platform.

• Serial ATA is a full duplex protocol. There is a continuous flow of signals from each device moving down the bus. The device and host are transmitting (TX) and receiving (RX) at the same time.
• Bidirectional traffic pattern eliminates the need for bus negotiation overhead
• Data characters vs Primitives - Primitives are the simplest elements within the Serial ATA protocol. Primitives are 32-bit DWORDs used to initiate control of the serial line functions (X_RDY, CONT, etc...). In addition to these "handshaking" and flow control signals, Primitives are also used to delimit or "frame" user data.
• Frame Information Structure (FIS) - A frame is an indivisible unit of information exchanged between a host and device. A frame consists of a SOF primitive, a Frame Information Structure (FIS), a CRC calculated over the contents of the FIS, and an EOF primitive. A FIS is the user payload of a frame; a frame is a group of Dwords that convey information between host and device as described previously.

• Serial ATA Working Group
• SearchStorage Serial ATA Technology
• T13 Technical Committee

The Avalanche SATA analyzer is LeCroy's next generation system that decodes 6Gbps, 3Gbps and 1.5Gbps Serial ATA (SATA) traffic. Avalanche runs the SATASuite™ application. Powerful post-processing reporting and search tools allow users to find errors and their causes very quickly. This system is capable of connecting to four hosts and targets simultaneously. Raw bit recording allows for analysis down to the lowest possible level and the 4GB buffer can record very deep traces. Avalanche comes in a condensed package that is highly portable.

The Avalanche SATA analyzer system does more than just record traffic moving across 4-Wide links. Using the SATASuite application, it provides a time-synchronized view, both at the DWORD and the Frame level for all four links. Plus it logically groups all frames that are part of a common operation - even if they are spread across multiple physical pathways. This eliminates the need to decode SATA transactions manually and helps you find problems faster.

• Four SATA analysis ports (6, 3 or 1.5 Gbps) - Monitor, trigger and record up to 4 Serial Attached SCSI links simultaneously
• State Machine Triggering - Isolate areas of interest with real-time hardware triggering
• Hardware Filtering - Extend capture window by removing non-essential primitives from the recording
• Raw Bit Recording - Analyzes traffic at the lowest possible level
• SAS Zoning and Multiplexing Capable - Capture, record and analyze traffic in complex storage network environments
• Link Tracker Display - Chronologically display all DWORDs on all channels synchronized to a common clock
• Frame Tracker Display - Summary view shows transport level events in a time synchronized table format
• Cascade Multiple Analyzers - By cascading up to 8 analyzers, time correlated traces for up to 32 channels can be recorded
• Traffic Summaries - Statistical reports provide high-level abstraction of events, operations, errors and OOB transactions
• Collapsible / Expandable Headers - Easy "drill-down" on field structures for individual Frames, Commands and Tasks
• Automatic Decoding at OOB View, Frame and FIS Layers; and ATA Transactions - View high-level Serial ATA protocol events
• Field Upgradeable BusEngine Technology - Easily upgrade firmware to support new features
• Dynamically Allocated Memory Pool (4 GB) - Capture long recording sessions for analysis and problem solving

The Avalanche system is fully capable of recording at 6Gbps high-speed serial interfaces. It comes with 4GB of memory. The mini-SAS connectors can attach to 4 hosts and target devices simultaneously. A Hi-Speed USB port is used to upload the captured data to the host. The heart of the Avalanche platform is the revolutionary BusEngine™. This state-of-the-art protocol processor core incorporates a real-time recording engine and configurable tools to trigger and filter SATA traffic at full line rate. All bus engine logic is fully field-upgradeable. It can selectively monitor traffic on specific channels or from a specific SATA port number. It can start recording when event counters or timers exceed specified thresholds.

For efficient development of Serial ATA systems and components, an analyzer has to let you extract useful information from a crowded stream of traffic, and accurately identify and selectively record what interests you most. SATASuite provides real-time hardware triggering on the critical components of Serial ATA including out-of-band signals, errors, commands, and primitives.

The Avalanche system features the state-of-the-art BusEngine core. This real time recording engine works can intelligently monitor and cooperatively trigger across 4 fully loaded SATA links. It discards idles and packs redundant symbols to save recording memory and can filter out primitives or truncate data payloads to maximize the efficiency of your recording memory. By removing redundant primitives or data payloads from the trace, you can focus your analysis on commands, status and flow control fields.

With 256 levels of trigger logic and up to six trigger states per level Avalanche is particularly effective at trapping intermittent problems that only occur during overnight testing. Multiple if/then/else/goto conditions can be programmed for isolating very specific situations. The triggering and filtering options are channel independent and can record different fields based on the traffic detected on the individual links.

You can configure the depth of the recording memory up to 4Gbytes and determine where in the recording the trigger is located. Filtering strategies can significantly extend the recording memory. A full complement of bus usage graphs is available which makes spooled recording useful for characterizing performance over an extended period.

Using SATASuite software to analyze trace data makes it easy to identify problems and explain behavior. SATASuite trains your eye to understand more information faster. Colors and graphics are used to represent trace elements in the context of the Serial ATA protocol. Sequences are shown on separate rows with every field labeled and color-coded. Errors are identified and highlighted in red. The negotiated link rate and out-of-band signaling are clearly labeled.

LeCroy pioneered the "hierarchical" approach to showing high level events which can be collapsed and expanded to reveal FIS, status fields, data payloads, and primitives. SATASuite provides exceptional "drill down" to byte level detail including raw 8b10b symbols. The Link Tracker display allows you to see DWORD level data streams in a table view. It uses a common reference clock to time synchronize traffic moving upstream and downstream on a full-duplex SAS link. It can display Packet fields, 10B HEX, Scrambled or unscrambled DWORDs. For Avalanche systems connected to multiple channels, it displays additional columns showing DWORD traffic chronologically across all links. This level of detail is critical to debugging command queuing because it provides precise timing context for analyzing state transitions within the SATA host controller. Frame Tracker moves one level higher by summarizing and displaying transport level events in a similar table format. Together, these two displays preserve the physical orientation of the recorded data, which makes it easier to visualize what's occurring on multiple SATA links.

The SATASuite display detects and alerts you 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. Vendor unique FIS's are also supported allowing trigger and decode of custom FIS types for developers implementing proprietary commands. Throughout the display, informative tool-tips give complete definition of each field's contents. In many cases, the display replaces the need to use a specification to understand the protocol.

Avalanche provides many mechanisms to measure and report on Serial ATA traffic. For each sequence in the trace, you can see an absolute time-stamp and delta time between sequences on the same link. You can specify the location of the timestamp and whether it's displayed in hex or decimal format.

A new Timing Calculator generates additional I/O metrics for any portion of a trace. For example, select any two points in a recording and automatically calculate the timing delta, throughput, payload and other statistics between two FIS or commands. The SATASuite Bus Usage analysis window includes graphical reports like Average Time to Data, which provides a snapshot of read efficiency.

Today's high bandwidth serial links require more automated analysis capabilities. With the Traffic Summary window, developers can evaluate throughput, timing, error rates and other statistical data at a glance - or navigate to individual fields. For example, by choosing a FIS, such as DMA Activate, you can automatically jump through each occurrence of that FIS Type on the trace. This traffic summary can be printed, saved to text or emailed with a single keystroke.

VSE provides an API which allows third party applications to extract information from a SASSuite recording. This scripting language is capable of opening and parsing any size trace file to allow users to automate routine analysis tasks such as performing timing calculations between link and transport layer events or automating data compares for Header fields or command parameters like status, or LBAs.

VSE scripts can be run from the application to automate post-processing tasks

The perfect combination of power and portability, Avalanche meets airline carry-on regulations and adapts to any lab environment.