N5412E Serial Attached SCSI-4 (SAS-4)

Introduction

Verify and debug your SAS devices faster and more easily

Keysight Technologies, Inc. Serial Attached SCSI-4 (SAS-4) compliance test software for Infiniium Series oscilloscopes provides you with a fast and easy way to validate and debug your SAS 1.5, 3.0, 6.0, 12.0 and 22.5 Gbps silicon, host bus adapter, initiator, high-density disk drive or enclosure backplane. It also supports automated SAS out-of-band (OOB) and loop back signal tests with the 81134A pattern generator, N4903B JBERT with Option 002 and M8020A JBERT. The SAS test software allows you to automatically execute SAS electrical checklist tests at each of the IT and CT interface points and displays the results in a flexible report format. In addition to the measurement data, the report provides a margin analysis that shows how closely your device passed or failed each test.

To make measurements with the SAS-4 test software, you also will need a method of connecting to the SAS interface on the electrical mating surfaces of your SAS connector.

Wilder Technologies (www.wilder-tech.com) provides test fixtures for SFF-8482, SAS-3 and SAS-4 x2 internal drive/backplane connector interfaces for SAS 1.5, 3.0, 6.0, 12.0 and 22.5 Gbps. In addition, the Mini-SAS HD test fixtures for SAS-3 and SAS-4 plug and receptacle interfaces are available from Wilder Technologies.

The SAS-4 test software performs a wide range of tests required to meet the physical layer requirements. The SAS-4 test software helps you execute the most difficult physical layer tests for transmitters (TX tests only), at the near-end (IT/CT interfaces) of a SAS link, that can be measured with a combination of a 33-GHz or higher real-time oscilloscope and the 81134A, N4903B or M8020A programmable pulse/pattern generator. The SCSI Trade Association currently sponsors at least one interoperability plugfests annually for member companies to test their products’ operational capability and margins with other member companies’ products.

With the SAS-4 test software, you can use the same oscilloscope you use for everyday debugging to perform automated testing and margin analysis based on the requirements in the SAS-4 specification.

SAS-4 Test Software Saves You Time

The SAS-4 test software saves you time by setting the stage for automatic execution of SAS electrical tests. Part of the difficulty of performing electrical tests for SAS is connecting the oscilloscope to the target device, configuring the scope’s measurement system for testing, issuing the proper commands to perform the tests and then analyzing the measured results by comparing them to limits published in the specification. The SAS electrical test software does much of this work for you. In addition, if you discover a problem with your device, debug tools in the scope are available to aid in root-cause analysis.

The SAS-4 test software offers the required tests to verify conformance with the physical layer parameters. The software automatically configures the oscilloscope for each test, and it provides an informative results report that includes margin analysis indicating how close your product is to passing or failing that specification. See Table 1 for a complete list of the measurements made by the SAS-4 test software.

Easy test definition

The SAS-4 test software extends the ease-of-use advantages of Keysight’s Infiniium Series oscilloscopes to testing SAS designs. The Keysight automated test engine walks you quickly through the steps required to define the tests, set up the tests, perform the tests, and view the test results. You can select a category of tests all at once, or specify individual tests. The user interface is oriented to minimize unnecessary reconnections, which saves time and minimizes the potential for operator error. You can save tests and configurations as project files and recall them later for quick testing and review of previous test results. Straightforward menus let you perform tests with a minimum of mouse clicks.

Meet test fixture requirement

SAS-4 specification has a new recommendation of the insertion loss profile of the test fixture being used for testing. The intents are to more accurately test the 22.5 Gbps signal without the effect of test fixtures so the industry can get more consistent results and avoid marginal design from passing using better test fixtures, but not meet the actual performance in real world. The SAS-4 test software includes the capability to embed and de-embed loss to the test fixture to ensure it meets the insertion loss requirement.

Configurability and Guided Connections

The SAS-4 test software provides flexibility in your test setup. When the tests you select require it, the software guides you to make connection changes with hookup diagrams. The SAS electrical test software provides you with user-defined controls for critical test parameters, such as interface, line baud rate and number of unit intervals (UI) desired for the test group.

After configuring the tests according to your needs, the user interface displays the connection screen that is specific to the configuration data you have selected. This includes the oscilloscope channels used for the test and the routing of any necessary SMA cabling, power dividers and test fixtures needed to perform the tests.

Reports with Margin Analysis

In addition to providing you with measurement results, the SAS-4 test software provides a report format that shows you not only where your product passes or fails, but also reports how close you are to the limits specified for a particular test assertion. You select the margin test report parameter, which means you can specify the level at which warnings are issued to alert you to the electrical tests where your product is operation close to the official test limit defined by the specification for a given test assertion.