TekExpress compliance test automation framework delivers architecture to support serial data test automation needs

Steadily increasing serial data rates require stringent standards and advanced compliance testing solutions. This has led to a demand for dramatically higher performance test and measurement instrumentation along with support for transmitter, receiver and channel testing. Meeting this demand not only requires a broad product portfolio but also a comprehensive and extensible compliance test automation software platform able to meet current and future needs. Tektronix instrumentation and the new TekExpress compliance test automation framework meet this demand with automated one-button testing for high-speed serial data standards. Initial support is for SATA.

Tektronix has launched what’s said to be the world’s fastest real-time oscilloscope, the DSA70000 Series Digital Serial Analyzer, that at 20 GHz enables debugging and analysis for standards up to 12.5 Gb/s and 5th harmonic measurements up to 8 Gb/s. The breakthrough AWG7000 series of arbitrary waveform generators support direct synthesis of multi-Gbps serial signals up to 6 Gb/s. These instruments provide ample performance for today’s 2nd and 3rd generation high-speed serial standards. Further, Tektronix is taking an active role in the standards bodies driving and improving test methodologies.

One of the more daunting challenges facing designers has been standards compliance testing. The latest standards require that multiple instruments and the device under test be simultaneously controlled. Market pressures for productivity combined with the rapidly growing number of required complex measurements – more than 150 in the case of SATA Gen-2 – mean that automation and test repeatability is becoming a must. As standards are frequently updated, designers need the ability to add and modify test procedures and parameters quickly and easily. Moreover, tests and results from multiple instruments need to be combined and the tests often need to be run several times.

TekExpress provides all the elements needed in a compliance test framework including a graphical user interface, control libraries, compliance test automation scripts, report generation, instrument discovery, and test result database management. The TestStand test management environment from National Instruments was chosen as the test executive for its rich variety of sequencing support and interfaces to many different design environments. TestStand also benefits from a large developer community that allows TekExpress Framework customers to extend their solutions to meet specialized requirements. Control libraries supported include ICP (instrument control proxy), SCP (solution control proxy), and ACP (analysis control proxy).

Built on top of the TekExpress compliance test automation framework is test automation software for a particular standard, such SATA Gen-1 and SATA Gen-2. Controlled from a Windows XP PC through an intuitive user interface, new TekExpress SATA automated compliance test software orchestrates the instrument setup and control sequences to provide complete certification test results quickly and efficiently. In the case of TekExpress SATA, all four SATA-IO approved Methods of Implementation (MOIs) can be completed in less than 3 hours of total elapsed test time, representing a reduction in compliance test time of approximately 70%.

The software automatically (or on demand) scans and detects supported instruments instruments), whether they are connected through LAN, GPIB, or USB. In addition to Tektronix instruments, a RF Switch from Keithley and a Frame Error Counter from Crescent Heart Software (CHS) are supported at the initial launch. (TekVISA™ is a standard software feature allowing instruments to be placed under the control of software applications (e.g. LabView, Microsoft Excel, C, TekExpress, TestStand, etc.) running on the instrument, or on external PC workstations network connected to the instrument.

Once the test bench is set-up and the DUT is properly connected, the user simply presses a “Run” button to perform the selected test suite. Online help is available through a help menu and provides direct access to reference information such as setup diagrams and the approved SATA MOI provided with TekExpress SATA. This allows engineers and test technicians to understand the theory behind the measurements and better understand test results.

After the tests are completed, the user can obtain an HTML view of test results along with Pass/Fail status and a scorecard. This scorecard can then be submitted for official compliance certification by test houses and at compliance workshops. Once the scorecard has a 100% passing score, the underlying DUT can then be considered compliant.

For device validation, it’s often desirable to make multiple runs of a single device using different operating conditions such as temperature and power supply voltages. This is sometimes referred to as four corners testing, (testing to low-high temperature and low-high supply voltages). For four corners testing, NI TestStand supports drivers for a wide range of temperature chambers and power supplies. NI TestStand can be used to control the temperature chamber and then call the Command and Control API within TekExpress compliance test automation framework for a compliance test. For adjusting power supply voltages, the power supply control sequence file within TekExpress can be modified using a standard NI TestStand sequence file. This is especially useful for a company that already uses TestStand for automation, allowing test engineers to incorporate Tektronix compliance scripts directly into their test sequences.

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