SAS Sierra M6-4

Serial Attached SCSI (SAS) is the next-generation replacement of SCSI Ultra320. SAS is a serialized protocol. The serial interface offers several benefits over the existing SCSI parallel bus; allowing for high availability, complex storage topologies, and a lower cost structure.

High Availability: As with SATA, Serial Attached SCSI is a high-speed, point-to-point technology initially designed to operate at speeds up to 6Gb/sec. System designers have found that point-to-point serial connections are inherently more reliable than shared bandwidth parallel connections. As a result, point-to-point serial connections have become the preferred method for implementing high-availability systems. SAS based disk drives are dual ported, taking advantage of this feature. This is a key requirement of high-availability SANs that call for redundant paths to all devices in the system.

Complex Storage Environments: SAS storage environments usually consist of a mixture of disk drives, host bus adapters and expanders. SAS allows for addressing of over 16,000 devices. SAS Expanders are routing devices that forward service requests between the source and destination devices. Expanders can be attached to other expanders, disk drives, and other hosts. An important characteristic of Expanders is their ability to aggregate bandwidth by combining multiple physical links into a "Wide" port. These wide ports can function as intelligent switches and can independently send commands across one physical path with data being returned over a different physical path. This increases the complexity of SAS test and debug because it requires users to monitor multiple links concurrently to record all DWORDs associated with a single SCSI transaction. The usage of expanders also allows for usage of a storage concept called Zoning. Zoning allows administrators to restrict access to devices by other devices. Applications of this include separating storage systems within a company by department.

Lower Cost Structure: Serial Attached SCSI also contains support for SATA drives in its storage environments. This allows support for both enterprise-class performance offered by SAS and low cost storage with SATA drives in the same system. Since the cost of the SAS infrastructure is expected to be comparable to SATA, it is likely that SAS will be the preferred interface. Since both SAS and SATA drives can be used in this environment, it will simplify and standardize the storage infrastructure, allowing for the ability to choose which drive will best fit individual storage needs.

SAS Test and Verification: LeCroy's protocol analysis tools are designed from the ground up to address these unique characteristics of SAS including wide-links and Serial ATA interoperability. Sierra’s analysis and design suites are developed specifically for use with the SAS and SATA protocols, and provide extensive protocol decoding, expert error analysis, and complete user support when decoding and viewing the recorded traffic. This extensive protocol support, combined with the different traffic views, advanced triggering, data filtering, traffic generation, and error injection capability, allows engineers to rapidly become familiar with SAS- and SATA-specific issues, and quickly understand new issues the first time they encounter them. Every engineer becomes a protocol expert with the support of Sierra’s detailed expert analysis.

Leveraging LeCroy's extensive expertise in high-speed serial data analysis, the Sierra provides the most accurate capture, display and analysis of both SAS and SATA data traffic at data rates up to 6 Gb/s. The Sierra product family includes the capability for protocol analysis, traffic generation, host and/or device emulation, and error injection, all within one system. The platform supports all features, and customers can configure specific features or add features later to match their requirements and budget.

With the flexibility to adapt to a user's current and future needs, the Sierra M6-4 System brings a new standard for performance, capability and flexibility to SAS/SATA protocol test systems.

The Sierra SAS/SATA Protocol Test System combines creative industrial styling and a performance-enhancing native PHY with expert software features that minimize debug and development time. The Sierra platform integrates the best of the STX and CATC Trace software suites and adds additional capabilities at both the hardware and software levels.

Sierra's analysis and design suites are developed specifically for use with the SAS and SATA protocols, and provide extensive protocol decoding, expert error analysis, and complete user support when decoding and viewing the recorded traffic. This extensive protocol support, combined with the different traffic views, advanced triggering, data filtering, traffic generation, and error injection capability, allows engineers to rapidly become familiar with SAS- and SATA- specific issues, and quickly understand new issues the first time they encounter them. Every engineer becomes a protocol expert with the support of Sierra's detailed expert analysis.

The Sierra platform is designed for convenience, portability, and functionality. Both data bus ports are located in the front for convenient access, as are all system controls and connectors (other than the AC power cord). The Sierra's array of status indicators includes information on negotiated link speed, protocol error detection, link detection, and whether OOB or protocol frames are currently being sent over the link. The LCD screen reports which user is currently connected to the Sierra system, the system IP address and system status. Host connectivity to the Sierra includes support for both USB 2.0 and Gigabit Ethernet. Expansion ports allow for future enhancements, such as providing DC power to a drive. The Sierra enclosure also includes flexibility for use either standalone on a workbench or integrated into a 19" rack.

One of the biggest new features for the Sierra platform is the addition of native PHYs. The native PHYs offer many benefits over implementations found in other 6G test solutions, including better capture performance during speed negotiation and power management phases, and improved response time with our comprehensive design suite. See more, miss less with the most capable PHY in the market.

	Native PHY	Current Implementation
Worst Case Lock Time	< 200ns	> 65us
Response Latency	9 DWORDS = 60ns	15 DWORDS = 100ns

From the link layer to the application layer, the Sierra analysis suite offers a wide range of traffic views and tools to enable engineers to easily zero-in on areas of interest. For applications at the link layer, the column and Link Tracker views show the handshaking of primitives and frame composition from SOF to EOF. Data can be viewed in 8b, 10b, and scrambled formats. When working at the frame level, the Text View shows exchanges of frames and accompanying primitives. For viewing commands and frames in a time-ordered fashion, the Spreadsheet View gives the user the flexibility to easily filter out unwanted primitives and frames to easily focus on what is important. The Sierra also features a hierarchical view for the application layer, logically assembling frames and primitives that are related to commands. The protocol-specific hierarchical view allows users to easily view command definitions, completion and status. This capability comes especially handy in environments with outstanding commands, large gaps of traffic between command start and command end, or other complexities such as Time-Domain Multiplexing. The commands can then be drilled-down to view the frame and link layers. All of the views for expert analysis can be used simultaneously and are automatically synchronized and displayed within one application. When developing or debugging, one size does not fit all. View the traffic in the manner most meaningful for the task.

From looking for a particular frame, to more complex events such as timing and status between events, Sierra's logical triggering algorithms give the engineer the ability to quickly define root issues to look for during capture. Sierra's powerful trigger capabilities include up to a 24-level state sequencer, 4 independent timers, multiple counters, the ability to pre-filter at each state, and the ability to assign individual triggers to each port pair. Defining fields within frames and/or commands is also easy thanks to protocol- specific awareness. Spend more time engineering and less time looking with the deepest trigger available.

With Sierra's transparent post-processing, searching, and hiding of unwanted traffic, analyzing the captured traffic has never been easier. Combined with protocol-specific awareness, post-processing allows the engineers to easily determine what was captured without having to scroll down and keep notes. From performance statistics, such as command throughput and completion time, to viewing how many times a command, frame, bus event, or primitive occurred, the traffic summary enables the engineer to easily track and find areas of interest. Sierra ZeroTime™ search immediately identifies what was actually captured, eliminating the possibility of searching for traffic that does not exist in the trace. Why waste time looking for events that never occurred? Use transparent intelligence to easily track-down and display areas of interest.

Sierra provides a wealth of statistical and performance reports, providing the means to easily monitor command execution, errors, and other data traffic issues. Selecting from the broad range of reports provides each customer with rapid access to the information you seek.

The Sierra system supports compliance testing to SAS and SATA standards to help insure interoperability between your product and other products under development or already on the market. By using a complete suite of SAS or SATA compliance tests, you have the assurance of an industry-standard test method.

The Sierra Trainer is a script-based traffic generator that gives engineers the ability to control what is being sent down to the bit level, including flexibility for changing OOB waveforms, defining IDLE traffic, and transmitting user-defined data patterns for customized testing throughout the design process. Also included is support for SAS compliance with our SAS Compliance Test Suite written in conjunction with the UNH-IOL (University of New Hampshire Interoperability Lab). The host and device emulators feature easy-to-use logic control and protocol-specific command and frame definition. Engineers can easily use the emulators to test command support and error-handling features of their device throughout the design bring-up process. The host and device emulators also support Serial ATA protocol compliance testing.

Sierra includes extensive error injection capability, and supports the InFusion™ 3.0 software test suite. InFusion provides the ability to monitor live traffic on heavily-loaded data buses at full data rates, and identify and modify traffic patterns "on-the-fly" to introduce programmed error conditions for testing error identification and recovery capabilities in the device under test. Examples include support for changing dwords, disconnecting links, and causing various errors (such as CRC and running disparity) at defined or random intervals. The InFusion test suite is especially useful during the final test and system integration cycles. Gain an edge over the competition with Sierra's comprehensive design suite.