SyntheSys Research Library

2008

SATA MOI - PHY/TSG: Serial ATA Interoperability Program Method of Implementation (MOI) for PHY and TSG Device Certification Tests using the BERTScope by SyntheSys Research, Inc. Revision 1.1, Version 1.0 • JULY 2007 • Final NOV 2008       Abstract + These Methods of Implementation describe the step by step procedures to perform the required PHY-01 through PHY-04 and TSG-01 through TSG-12 (except TSG-07 and TSG-08, which are optional for all components) tests of the Serial ATA Interoperability Program using the BERTScope by SyntheSys Research, Inc. in order to qualify a product for listing on the SATA Integrators List. The test setup is illustrated in Appendix B. The Lone Bit Pattern (LBP) used for Interoperability Testing is that which is defined per ECN 018 against SATA Revision 2.5. The tests may be performed in the sequence shown in Appendix D or automated using software shown in Test Title: Serial ATA Interop Test Suite. Contact SyntheSys Research, Inc. for the availability of software and accessories.   Download PDF - 1.6 MB

Demystifying Receiver Jitter Tolerance Testing • Presenter: Steve Sekel • ON-DEMAND WEBCAST hosted by EDN • SEPT 2008       Abstract + Although all serial data standards specify a required receiver jitter tolerance, compliance testing of the link physical layer has generally ignored the receiver. However as the data rates are increasing, the standards organizations are realizing that testing only the transmitter and relying on interoperability test to cover the receiver will not assure data integrity. Thus, the newer standards are beginning to incorporate receiver jitter tolerance testing as part of the “gold suite” of required compliance tests. During this test, a known compliance pattern is sent to the receiver, superimposed with a calibrated amount of jitter. Many designers who have only dealt with transmitter testing have questions of what is involved with a receiver test, and how to set it up correctly. This seminar fills the knowledge gaps by: • Explaining receiver testing • Giving insight into the sometimes complicated “recipe” of jitter sources used in the test, including random, periodic, duty cycle distortion, and inter-symbol interference. • Showing how these jitter sources relate to the interference mechanisms in the real communication channel. • Explaining how to properly calibrate the jitter sources to assure accurate testing to the standards, without overstressing the receiver. We will also discuss special requirements for testing receivers using spread spectrum clocking, or when transmitter pre-emphasis equalization is used.   Watch ON-DEMAND Webcast from EDN

Testing an SFP+ Transceiver to the 8x Fibre Channel Specifications, Part II • AUG 2008       Abstract + This paper examines the practical aspects of testing a limiting variant SFP+ transceiver for 8x Fibre Channel (8xFC or 8GFC) applications. It covers testing requirements for transmitter and receiver test points of an SFP+ module, including the 8GFC SFP+ high speed serial electrical interface (SFI) interface. It describes the significant tests required for compliance testing and details testing methods to assure the module meets the rigorous 8GFC standards established. Part I covers the basics of compliance testing to the Fibre Channel standard and gives an overview of the pertinent measurements and how they can be accomplished using BERTScope instrumentation. Part II leverages the foundation laid in Part I and continues with a practical example that demonstrates all aspects of compliance testing highlighted in Part I. (SR-TN077)   Download PDF - 3.2 MB

Testing an SFP+ Transceiver to the 8x Fibre Channel Specifications, Part I • AUG 2008       Abstract + This paper examines the practical aspects of testing a limiting variant SFP+ transceiver for 8x Fibre Channel (8xFC or 8GFC) applications. It covers testing requirements for transmitter and receiver test points of an SFP+ module, including the 8GFC SFP+ high speed serial electrical interface (SFI) interface. It describes the significant tests required for compliance testing and details testing methods to assure the module meets the rigorous 8GFC standards established. Part I covers the basics of compliance testing to the Fibre Channel standard and gives an overview of the pertinent measurements and how they can be accomplished using BERTScope instrumentation. Part II leverages the foundation laid in Part I and continues with a practical example that demonstrates all aspects of compliance testing highlighted in Part I. (SR-TN076)   Download PDF - 3.0 MB

Product Note: DCRj and OmniBER OTN 10 Gb/s Telecom Jitter Generation Correlation Study • MAY 2008       Abstract + The telecom Jitter Generation measurement is an indication of how much jitter is output at an optical interface (for example, an optical transmitter) and is a requirement in telecom testing to standards such as SONET/SDH and OTN. Historically, jitter analyzers have been used to perform this measurement. A new type of instrument, the BERTScope Digital Communications Receiver (DCRj) 11000A, is also capable of this measurement. In this paper, we compare the results of the DCRj to a jitter analyzer widely used in the industry to demonstrate good correlation as well as the ability of the DCRj to measure new data rates emerging in industry standards. (SR-TN075)   Download PDF - 2.8 MB

PCI Express (Rev1.1a) Test Methodology for PLL Loop Bandwidth Response in Add-in Cards - Testing Guide for: SyntheSys Research, Inc.'s PLL Analyzer Series BERTScope PLA, CRJ 125A-PCIE and PLL-PCIE • Revision 1.0 • PCI-SIG • APR 2008   Download PDF - 1.9 MB

PCI Express (Rev2.0) Test Methodology for PLL Loop Bandwidth Response in Add-in Cards - Testing Guide for: SyntheSys Research, Inc.'s PLL Analyzer Series BERTScope PLA, CRJ 125A-PCIE and PLL-PCIE • Revision 1.0 • PCI-SIG • APR 2008   Download PDF - 2.8 MB

The Impact of Clock Recovery on Your Serial Data Measurements • Presenter: Steve Sekel • ON-DEMAND WEBCAST hosted by EDN • APR 2008       Abstract + Clock Recovery is an important component in serial data measurements, whether evaluating the performance of transmitters, receivers or systems. The performance of clock recovery has a direct impact on accuracy and repeatability of these measurements. While engineers commonly spend considerable time trying to achieve jitter measurements which correlate, few consider the contribution of clock recovery performance. This seminar fills this knowledge gap, providing the engineer the information needed to improve measurement integrity. It covers: • How clock recovery instruments are applied in the test systems, and the parameters that affect jitter measurements.  • How PLL bandwidth and peaking alter the jitter transfer function through the system, and how edge density affects the calibration of these.  • The differences between hardware and software PLL implementation.  • The inaccuracies resulting from trigger latency and unmatched data and clock path delay. Take a big step toward higher accuracy jitter measurements by increasing your understanding of this key aspect of your measurement system.   Watch ON-DEMAND Webcast from EDN

Optical Transmitter Jitter Measurement Basics • APR 2008       Abstract + While jitter is a familiar measurement is optical transmitter testing, it can be defined very differently depending on the context. We will compare and contrast the meanings for telecom standards such as SONET/SDH/OTN with those for enterprise and storage. We will explore eye diagram jitter compliance and the different philosophies behind bathtub jitter and the frequency banded jitter relied on in other standards. The implications for compliance and troubleshooting will be illustrated with measurement examples. This paper is based upon an e-seminar given by SyntheSys Research in January 2008 through Lightwave Magazine. (SR-TN074) See related On-Demand Webcast link below   Download PDF - 2.5 MB

Comprehensive Optical Stressed Eye and Transmitter Compliance Testing • APR 2008       Abstract + Combine the BERTScope S and BERTScope DCRj with the 1310 nm JDSU OPTX 10 Reference Generator, or with the 850 nm BERTScope LTS to perform stressed eye receiver tolerance and compliance testing up to 11.2 Gb/s. The test set is configurable for multiple data rates and provides both electrical and optical stressed eye testing for XFP/XFI, 2x, 4x, and 10x Fibre Channel, and 10GbE at 850, 1310, or 1550 nm wavelengths. This solution gives design and test engineers deep insight into device performance with eye diagram, jitter peak, jitter spectrum, compliance contour, and BER contour analyses. • Accurate analysis of stress elements to provide calibrated signal at the test device input • Automated testing to standard or custom jitter tolerance templates with user-defined stress margins • Optical reference transmitter with pre-calibrated, adjustable extinction ratio • Test to standards requiring compliant loop bandwidth clock recovery using the BERTScope DCRj • 10 Gb/s Transmitter Compliance Testing • SONET, SDH, and OTN Jitter Generation Analysis including 11.1 Gb/s (SR-DS017)   Download PDF - 2.7 MB

Combating Closed Eyes: Pre-Emphasis and Equalization Basics • APR 2008       Abstract + Pre-emphasis and equalization are signal processing techniques that are increasingly popular solutions to signal integrity problems caused by lossy backplane channels at high signaling rates. The goal of this paper is to show how channel loss manifests itself and how pre-emphasis and equalization can be used to counteract this loss. We will also examine how pre-emphasis affects test and measurement with examples pulled from popular standards. We conclude with some practical examples of pre-emphasis and equalization filters across a high speed backplane. (SR-TN073) See related On-Demand Webcast link below   Download PDF - 2.2 MB

DisplayPort MOI - Sink: VESA DisplayPort MOI, Method of Implementation, for DisplayPort Sink Jitter Tolerance Tests Using BERTScope 7500B by SyntheSys Research, Inc., Ver. 0.26 • OCT 2007 (Released FEB 2008)   Download PDF - 6.6 MB

Signalintegritätsanalyse und Compliance Testing (Signal Integrity Analysis and Compliance Testing) • article published in electronik industrie • Michael Riess, Laser 2000 • FEB 2008       Abstract + Mit den BERTScopes ist es möglich, Bitfehlermessungen mit Augendiagramm- und Augenkonturmessungen zu korrelieren. Sehr schnelle Maskentests, Jitter-Peak, Q-Faktor und Jitterspektrumanalyse geben weitere Information über die Qualität der untersuchten seriellen Datensignale. Eine detaillierte Fehleranalyse, ausgehend von der Augendiagrammdarstellung bis hinunter auf Bitebene, wird so möglich. [With the BERTScope it is possible to correlate bit error measurements with eye diagram and eye contour measurements. Very fast mask tests, jitter peak, Q-factor, and jitter spectrum analysis give further information about the quality of the examined serial data signals. A detailed error analysis, on the basis of the eye diagram representation down to the bit level, becomes possible.] This English translation of the abstract is for convenience; the article is available in German only.   Download PDF - 0.2 MB     Read at elektronik industrie

Transmitter Jitter Basics: Two Worlds of Test • Presenter: Charlie Schaffer • ON-DEMAND WEBCAST hosted by Lightwave • JAN 2008       Abstract + While jitter is a familiar measurement in transmitter testing, it can be defined very differently depending on the context. In this webinar we compare and contrast the meanings for telecom standards such as SONET/SDH/OTN with those for enterprise and storage. We explore eye diagram jitter compliance and the different philosophies behind bathtub jitter and the frequency banded jitter relied on in other standards. The implications for compliance and troubleshooting are illustrated with measurement examples. (See related white paper above)   Watch ON-DEMAND Webcast from LIGHTWAVE

Product Note: Telecom Jitter Analysis Using the BERTScope and BERTScope DCRJ • JAN 2008       Abstract + Fiber Optic transmission systems are continuing to push data rates to higher levels. As rates increase, so does the negative contribution of jitter in networks. Understanding and controlling jitter throughout the network is key to error free transmission. Optical transceivers are a significant component in telecom network equipment. For an optical transceiver, it is important to establish if: • The device receiver can tolerate enough incoming jitter (jitter tolerance) • The device transmitter produces too much jitter (jitter generation) • Passing jittered data through the device causes an excessive increase (gain) in jitter on the data being re-transmitted (jitter transfer) In this paper we look at telecom jitter standards SONET, SDH, and OTN, and how jitter affects error free transmission. Also, through a practical example measuring an XFP transceiver we verify the SONET jitter standard using the SyntheSys Research BERTScope S and BERTScope DCRj, capable of testing beyond 11.1 Gb/s. (SR-TN072)   Download PDF - 2.7 MB

DisplayPort MOI - Source: VESA DisplayPort MOI, Method of Implementation, for DisplayPort Source PHY Compliance Tests Using the BERTScope by SyntheSys Research, Inc., Ver. 0.19 • OCT 2007 (Released JAN 2008)   Download PDF - 4.4 MB

2007

Pass PCI Express Physical Layer Compliance Testing the First Time • Presenter: Bent Hessen-Schmidt • ON-DEMAND WEBCAST hosted by Test & Measurement World and EDN • DEC 2007       Abstract + With the PCIe 2.0 specification, 5.0 GT/s and 2.5 GT/s receiver testing are emerging as key requirements for chip designers and add-in card vendors. In this seminar we look at why the requirements have been set the way they have, and some of the practicalities of making the measurements. We will then look at key transmitter measurements such as PLL characterization, jitter measurement in the presence of de-emphasis, de-emphasis ratio, and dual port measurements. Measured examples of real devices will be used to illustrate the requirements.   Watch ON-DEMAND Webcast from Test & Measurement World/EDN

Combating Closed Eyes — Design and Measurement of Pre-Emphasis and Equalization for Lossy Channels • Presenter: Tom Waschura • ON-DEMAND WEBCAST hosted by EDN • OCT 2007       Abstract + This seminar introduces the need for pre-emphasis and equalization for high-speed serial communication over lossy channels such as backplanes, cables and connectors. In order to overcome the inter-symbol interference caused by frequency dependent channel losses, inverse transfer functions can be computed and applied at various points of the signal processing to enable error-free bit detection. Circuits are described that implement inverse transfer functions such as pre-emphasis and equalization, and that include digitally clocked finite impulse response filters, linear finite impulse response equalizers as well as decision feedback equalizers (DFE). Following the theoretical filter development, examples are presented that derive optimized impulse response filter taps from step response or frequency domain network analysis measurements. Measurements are discussed and examples are used from standards such as PCI Express Generation 2. (See related white paper above)   Watch ON-DEMAND Webcast

PCI Express 5.0 GT/s Add-In Card Receiver Testing, Rev. 1.1 • DEC 2007       Abstract + The need to relieve throughput bottlenecks in computing and communications, together with the development of low cost, high speed CMOS technology, has caused the move to high speed serial buses. PCI Express® (PCIe®) is aimed at replacing PCI for applications such as interfacing video cards in computing. Because the PCIe serial data rates of 2.5 GT/s and 5.0 GT/s are in the microwave range, they require significant attention to signal integrity for successful compliance testing. Testing can be done at two levels: the Base Specification; or the Card Electro-Mechanical (CEM) level, a subset of the full base specification used for compliance workshops. This document describes testing to verify receiver compliance with the PCI Express Base Specifications Revision 2.0 and highlights three important areas in receiver compliance testing: • Jitter generator requirements including clock recovery • Calibration channel requirements • Compliance baseboard configuration requirements (SR-TN071)   Download PDF - 2.2 MB

PCI Express 2.5 GT/s Add-In Card Receiver Testing, Rev. 1.1 • DEC 2007       Abstract + Add-in cards designed for PCI Express require numerous tests to assure inter-operability with different systems. This document describes testing to verify receiver compliance with the PCI Express Architecture PHY Electrical Test Considerations, PCI Express Card Electro Mechanical Specifications, and PCI Express Base Specifications Revision, and highlights three important areas in receiver compliance testing: • Jitter generator requirements • Compliance Base Board (CBB) configuration requirements • Clocking Requirements (SR-TN070)   Download PDF - 1.8 MB

PCI Express Transmitter PLL Testing — A Comparison of Methods • SEPT 2007       Abstract + The electrical compliance test specification drafted by PCI-SIG requires testing loop response of the Phase Locked Loop (PLL) used in add-in cards to generate a local transmitter clock from a 100 MHz reference oscillator. There are several possible methods for performing this test. This paper provides an overview of the significant ones, including one method based on an instrumentation-quality clock recovery instrument. The clock recovery method is a single-instrument solution that provides superior test accuracy, resolution, and throughput at minimal cost. The measurement output results are displayed directly without the need for interpretation, minimizing chances for operator error. (SR-TN067)   Download PDF - 0.2 MB

PCI Express 2.5 GT/s Add-In Card Transmitter Testing, Rev. 1.1 • SEP 2007       Abstract + Add-in cards designed for PCI Express® require numerous tests to assure inter-operability with different systems. This document describes testing to verify transmitter compliance with the PCI Express Card Electromechanical Specifications Revision 1.0a, Revision 1.1, and Revision 2.0, and highlights three important areas in compliance testing: • Accurate views for de-emphasis measurements • Edge density requirements for clock recovery • The speed of making mask tests (SR-TN062) Previously titled "PCI Express 1.0a and 1.1 Add-In Card Transmitter Testing"   Download PDF - 1.5 MB

“Gigabit Signal Integrity Creates New Challenges” • article published in the BestTest Newsletter • AUG 2007       Abstract + It is well documented that many parallel data transfer architectures used in computing have switched over to higher speed serial data streams at Gigabits/sec. Examples include graphics card data (PCI to PCI Express) and storage communications (Parallel ATA to Serial ATA). The telecommunications industry has dealt with these higher speeds for a lot longer, but has not been forced to meet such stringent cost constraints. By engineering down to a competitive price, serial bus standards do not enjoy use of exotic microwave materials, nor are they allowed significant performance margins to make links work. A decade or two ago, signals with these frequency components would have been carried in waveguides, but to pass them across the types of circuit board materials of an average motherboard, engineers have had to get creative. (SR-TN068)   Download PDF - 377 kB     Read article at BestTest

SATA MOI - RSG: Serial ATA International Organization Interoperability Program, Revision 1.2, Version 1.0, Method of Implementation (MOI) for RSG Tests (using BERTScope 7500B with CR) • AUG 2007       Abstract + These Methods of Implementation describe the step by step procedures to perform the RSG-01 through RSG-02 tests of the Serial ATA Interoperability Program using the BERTScope by SyntheSys Research, Inc., to qualify a product, host or device, for listing on the SATA Integrators List. Described methods can test products which support disconnect as well as products without support of disconnect. The test setup is illustrated in Appendix B. The Framed COMP pattern used for Interoperability Testing is that which is compliant with the definitions of SATA Revision 2.6 and approved ECNs against Revision 2.6. The tests can be performed in automated fashion using Jitter Tolerance software available on the BERTScope. Please contact SyntheSys Research, Inc., for the latest information on such software.   Download PDF - 3.1 MB

SATA MOI - PHY/TSG: Serial ATA Interoperability Program Method of Implementation (MOI) for PHY and TSG Device Certification Tests using the BERTScope by SyntheSys Research, Inc. Revision 1.1, Version 1.0 • JULY 2007 • Final NOV 2008       Abstract + These Methods of Implementation describe the step by step procedures to perform the required PHY-01 through PHY-04 and TSG-01 through TSG-12 (except TSG-07 and TSG-08, which are optional for all components) tests of the Serial ATA Interoperability Program using the BERTScope by SyntheSys Research, Inc. in order to qualify a product for listing on the SATA Integrators List. The test setup is illustrated in Appendix B. The Lone Bit Pattern (LBP) used for Interoperability Testing is that which is defined per ECN 018 against SATA Revision 2.5. The tests may be performed in the sequence shown in Appendix D or automated using software shown in Test Title: Serial ATA Interop Test Suite. Contact SyntheSys Research, Inc. for the availability of software and accessories.   Download PDF - 1.6 MB

Integration Technologies for Pluggable Backplane Optical Interconnect System • Alexei L. Glebov, Michael G. Lee, Kishio Yokouchi • Fujitsu Laboratories of America (First published by SPIE in Optical Engineering, Vol. 46, Iss. 1, 015403) • JAN 2007       Abstract + Integration technologies for board-to-board optical interconnect systems are presented. In the module architecture, optical transmitters and receivers are placed on the line cards and the signals are routed to the optically passive backplane through optical jumpers. The back-plane contains a light guiding layer with embedded polymer waveguides (WGs) and 45-deg reflector micromirrors. The WGs are fabricated by direct lithographic patterning and have propagation losses as low as 0.05 dB/cm. The wedge dicing technology is developed for fabrication of the 45-deg micromirrors with 0.5-dB excess losses. The pluggable optical connectors with microlens adaptors couple the light from the optical jumpers into the backplane WGs. Evaluation of the connector alignment tolerances demonstrates a very weak dependence of the coupling efficiency on the axial displacement and a more significant effect of the radial shifts. The presented results show that the displacement tolerances can be substantially improved with auxiliary lenses formed on the substrate. Prototype optical interconnect modules with integrated channel WGs, mirrors, and assembled connectors are fabricated with insertion losses of 5 to 6 dB. The modules successfully pass the high-speed transmission tests at data rates up to 11 Gbit/s.   Download PDF - 1.6 MB

2006

Product Note: 10 Gb/s Optical Transmitter Testing • DEC 2006       Abstract + Optical transmitter testing is a key cost element in the manufacturing of transceivers and their subcomponents. Accuracy, repeatability, and test speed all play their part. In this paper we look at some important common transmitter measurements and how they are made with a SyntheSys Research BERTScope-based setup. In addition, we look at how example results compare with those made with two common sampling scope solutions. (SR-TN064)   Download PDF - 0.9 MB

Clock recovery's impact on test and measurement • published in LIGHTWAVE • NOV 2006       Abstract + Clock recovery plays a significant role in making accurate test measurements, whether incorporated into the test setup or as part of the device under test. As most gigabit communication systems are synchronous, the data within them are timed against a common clock. Whether traveling across inches of circuit board or traversing continents on optical fiber, the relationship between the data and the clock they were timed against can become disturbed. By extracting clock directly from the data, signal regeneration at the receiver can be achieved correctly. It is important to note that receivers typically improve the incoming data signal before passing it on. A decision circuit in the receiver re-times the data and squares up the pulses. This process depends on a clock signal that is synchronous with the incoming data. Clock recovery within the receiver achieves this goal, provided the re-timing clock moves in the same way and at the same time. (SR-TN063) Download PDF - 84 kB  Article reproduction (not printable) - 201 kB    Read article at LIGHTWAVE

Signal Integrity Success in Computer and Storage Applications • OCT 2006       Abstract + With the transition from parallel to high speed serial computer communications, test methodology is also changing. Compliance testing continues to evolve, with new signal conditioning schemes to be validated and renewed focus on transmitter and receiver tolerance testing. For a design engineer, challenges tend to be two-fold - whether a design passes compliance, and getting to root cause issues if it does not. This brochure gives some examples of how the BERTScope family has proved useful to our customers in both areas, starting with serial bus compliance testing. Almost all of the examples used in this brochure are documented in more detail in literature from SyntheSys Research. Reference numbers are given with each section, and the source documents listed on the last page. (SR-DS020)   Download PDF - 1.6 MB

SAS Receiver Jitter Tolerance Testing • SEPT 2006       Abstract + Serial Attached SCSI (SAS) is a serial communication protocol for computer storage devices. It is designed as a replacement for SCSI, allowing for much higher speed data transfers than previously available with the parallel communication method of traditional SCSI. SAS is backwards compatible with Serial ATA (SATA). SAS electrical receivers are required to pass a test of their jitter tolerance using a stressed eye. The following tools are needed to make such a test: • A jitter generator with common mode interference mode. • An interference injection and test load (if testing a SATA device) both compliant with the 100 +/- 15-ohm impedance (21.8 dB return loss) requirement. • Compliance clock recovery with correct edge density setting for verification of the stimulus. This paper gives context to the requirements and describes the construction of a compliant stressed eye signal. (SR-TN061)   Download PDF - 0.6 MB

Measurement Brief: Introduction to Measurement of Skew, Including Methods for SATA and SAS Transmitter Compliance Testing • SEPT 2006       Abstract + In standards there is often a requirement to introduce skew into measurements to see whether the device under test copes. In this context, skew refers to a differential signal where the path length is different between each side of the differential pair. It can often be an unintended consequence of board layout routing, and also improperly matched test cables. Systems are usually designed to be able to tolerate a certain amount. This measurement note will look at several methods of measuring skew: a generic method, and then the methods for Serial ATA (SATA) and Serial Attached SCSI (SAS). They can be accomplished with a BERTScope and also applied to sampling oscilloscopes. (SR-TN053)   Download PDF - 0.4 MB

Serial ATA Gen2 Jitter Tolerance Testing • AUG 2006       Abstract + Serial ATA is an increasingly common serial bus technology aimed at disk drive applications. Electrical receivers are required to pass a test of their jitter tolerance using a stressed eye. This paper gives context to the requirements, and describes the construction of a compliant stressed eye signal. (SR-TN054)   Download PDF - 1.1 MB

Testing the High Speed Electrical Specifications of an XFP Transceiver • JULY 2006       Abstract + This paper takes a look at the practical aspects of testing an XFP transceiver. It covers testing requirements for the host system output (B´) and the XFP module output (C´). It describes the various tests required for compliance testing of an XFP transceiver and describes testing methods to assure the module meets the rigorous standards. (SR-TN060)   Download PDF - 2.0 MB

The Anatomy of Clock Recovery poster, Part 2 • Guy Foster • MAR 2006       Abstract + Our colorful, informative posters introduce basic principles and applications of foundational techniques in signal integrity testing. They are about testing digital high speed communications electronics, and are intended for electronics engineers who need to verify compliance of their products. The poster is approximately 27” x 38” (68.5 x 96.5 cm), printed in full color on glossy, heavyweight paper. “Clock recovery is a common part of many measurements, whether as part of the test setup of part of the device under test. We're going to look at clock recovery from a practical point of view, with emphasis on how it affects measurements… ” (SR-TN055b) See related white paper below   Request the poster

The Anatomy of Clock Recovery, Part 2 • MAR 2006       Abstract + Clock recovery is a common part of many measurements, whether as part of the test setup or part of the device under test. We're going to look at clock recovery from a practical point of view, with emphasis on how it affects measurements. This document closely mirrors the poster "The Anatomy of Clock Recovery, Part 2" and picks up where the paper "Clock Recovery Primer, Part 1" left off. (SR-TN059) See related poster above   Download PDF - 1.4 MB

The Anatomy of Clock Recovery, Part 1 • MAR 2006       Abstract + Clock recovery is a common part of many measurements, whether as part of the test setup or part of the device under test. We're going to look at clock recovery from a practical point of view, with emphasis on how it affects measurements. This document closely mirrors the poster "The Anatomy of Clock Recovery, Part 1." (SR-TN058) See related poster below   Download PDF - 1.0 MB

Measurement Brief: Exploring Power Supply Voltage Sensitivity in an IC • MAR 2006       Abstract + This short paper examines the signal integrity performance of an IC under the condition of lowered power supply voltage. It forms a classic example of why eye diagrams cannot be relied upon as the sole measure of system performance. (SR-TN057)   Download PDF - 0.2 MB

Measurement Brief: Signal Integrity of Reference Clock Bleed-Through in an IC • MAR 2006       Abstract + This paper examines some signal integrity examples related to AMB testing, but also with wider applicability. Clock bleed-through is examined, as well as the effect of lowered supply voltage on error performance. The latter is a classic example of why eye diagrams cannot be relied upon as the sole measure of system performance. (SR-TN056)   Download PDF - 0.3 MB

Measurement Note: Using the XFI 'EQ Filter' to Equalize a Channel to Enable Eye Measurements • FEB 2006       Abstract + The XFI 10 Gb/s electrical interface document describes eye measurement methods using a channel equalizing filter. This note gives a brief introduction to the topic, and shows measurements made on a suitable equalizing filter. (SR-TN052)   Download PDF - 0.5 MB

The Anatomy of Clock Recovery poster, Part 1 • Guy Foster • FEB 2006       Abstract + Our colorful, informative posters introduce basic principles and applications of foundational techniques in signal integrity testing. They are about testing digital high speed communications electronics, and are intended for electronics engineers who need to verify compliance of their products. The poster is approximately 27” x 38” (68.5 x 96.5 cm), printed in full color on glossy, heavyweight paper. “Clock recovery is a common part of many measurements, whether as part of the test setup of part of the device under test. We're going to look at clock recovery from a practical point of view, with emphasis on how it affects measurements… ” (SR-TN055a) (See related white paper above)   Request the poster

Stressed Eye: "Know what you're really testing with" • JAN 2006       Abstract + There are considerable differences between the way that 10 Gb/s Ethernet (10 GbE) and 4x Fibre Channel (4x FC) go about defining timing and amplitude settings for receiver jitter tolerance testing. These differences can be subtle, but can have an enormous impact on the test signal, and therefore on the success of the testing. The points raised here are equally applicable to other stressed eyes, both optical and electrical. (SR-TN051)   Download PDF - 1.3 MB

Constructing a 10 GbE Optical Stressed Eye • JAN 2006       Abstract + Following on from the Stressed Eye Primer, this paper looks at the practical construction of optical stressed eyes for 10 Gigabit Ethernet. It also examines the standard in more detail. It is a companion to a similar paper examining the 4x Fibre Channel standard. (SR-TN049) See also Stressed Eye Primer paper below   Download PDF - 1.7 MB

Constructing a 4x FC Optical Stressed Eye • JAN 2006       Abstract + Following on from the Stressed Eye Primer, this paper looks at the practical construction of 4x Fibre Channel stressed eye. It also examines the relevant standards in more detail. This is a companion document to one describing the construction of a 10 Gb/s Ethernet stressed eye. (SR-TN050) See also Stressed Eye Primer paper below   Download PDF - 1.7 MB

2005

Dual-Dirac, Scope Histograms, and BERTScan Measurements • SEPT 2005       Abstract + Much has been written about the strengths and weaknesses of dual-Dirac as a model for jitter measurement. The aim of this note is to give a gentle introduction to the topic, and how the dual-Dirac relates to practical measurements that can be made with sampling scopes and BER-based instruments. (SR-TN045)   Download PDF - 1.1 MB

Evaluating Stress Components Using BER-Based Jitter Measurements • SEPT 2005       Abstract + Stressed eye testing allows the introduction of different kinds of jitter components. How can the user tell whether the right amount is being introduced? What will different components look like when measured with deep BER-based jitter analysis? This paper examines these questions using the BERTScope S 12500A as the basis. (SR-TN046>   Download PDF - 1.1 MB

Stressed Eye Primer v. 1.1 • SEPT 2005       Abstract + Many high-speed serial interface standards call for a test known as 'Stressed Eye.' This paper is an introduction to stressed eye testing, some of the high-speed standards that use it, and how a receiver test using stressed eye is constructed. (SR-TN038) See also papers about constructing optical stressed eyes, above   Download PDF - 1.1 MB

Measurement Brief: Comparing Sampling Scope and BERTScope Jitter Measurements • JULY 2005       Abstract + Eye diagrams are constructed fro voltage samples taken at a rate many times lower than the data rate. The traditional method of measuring jitter on an eye diagram is to place a window around the eye diagram crossing point, and the build a histogram of the samples that were taken in that region alone. From the shape and width of the histogram, an estimate of jitter is made. There are a number of disadvantages of this approach. The biggest one is depth, or the fact that the source of data shows so little of what is really going on. Most sampling scopes take data at the rate of a hundred kilo-samples per second. The best (including the BERTScope eye diagram) are in the mega-samples per second range. (SR-TN043)   Download PDF - 0.4 MB

Measurements of Pre-Emphasis on Altera® Stratix® GX with the BERTScope 12500A • JUNE 2005       Abstract + This paper gives a brief overview of signal integrity measurements made with the Stratix GX device from Altera. It gives quantifiable measurement of the effectiveness of the pre-emphasis function that is available on the Stratix GX family. It employs Eye Diagram, Jitter and BER Contour functions of the BSA 12500A to reveal the part's performance. (SR-TN040)   Download PDF - 1.0 MB

Compliance Contour — Bridging the Gap between BER and Mask Testing for XFI, PCI-Express, OIF-CEI • JUNE 2005       Abstract + It's an age old problem - systems are expected to operate to better than 1x10^-12, but measurement to such levels takes too long. A straight BER measurement also doesn't indicate the margin available in the design. A solution to the speed problem has been to characterize a transmitter in terms of an eye diagram mask test, which is fast and lends itself to sampling scope-style measurement. Mask tests are usually shallow - an assessment of device performance will be made on a few hundred or thousand samples. The challenge is to use these shallow measurements to assess whether a device will exhibit problems that may be one in a billion. This is often achieved by extrapolation or de-rating - making the size of the mask sufficiently large or difficult, that a device that passes it must also be operating satisfactorily down to 1x10^-12. There are several problems with this, including the obvious risks of an extrapolation of nine orders or magnitude in any situation; there is also the danger that too stringent a de-rating has been specified in order to catch corner case problems, and consequently good devices are being failed needlessly. (SR-TN041)   Download PDF - 0.2 MB

The Importance of Delay Line Accuracy in Making Direct BERTScan Measurements • JUNE 2005       Abstract + Many standards use the BERTScan, or BER Bathtub, as the compliant method for measuring jitter. These include MJSQ, Fibre Channel, Gigabit Ethernet and many others. Some standards specify that the operating jitter performance must be measured down to a BER of 1x10^-12. Others allow some degree of extrapolation from measurements made at higher equivalent BERs, acknowledging that the accuracy will be lower. This paper will give some practical ways of quantifying the suitability of an individual instrument for making accurate and repeatable direct measurements to a specified BER level. (SR-TN039)   Download PDF - 0.2 MB

BERTScope-Based Signal Integrity Compliance Testing • Tom Waschura • JAN 2005       Abstract + Signal integrity compliance testing varies from application to application, but recurring themes are emerging to help multi-gigabit systems designers assure interoperability. Most of the tests needed to qualify a part or system can be performed with bit error rate testers and oscilloscopes; however a new generation of instrument, a BERTScope, takes advantage of naturally deep measuring capability, an integrated pattern generator (with calibrated stress), tightly-coupled eye diagramming, and bit error rate measuring functions to provide complete compliance testing. This paper describes the measurements necessary for compliance testing as well as the features and benefits of the BERTScope for this application. Measurements of transmitter jitter, channel performance and receiver tolerance are described. (SR-TN037)   Download PDF - 0.5 MB     View Design Con TecPreview online

2004

Selecting the Right Bit Error Rate Tester (BERT) • OCT 2004       Abstract + For any digital communications link, the ultimate measure of its physical layer performance is whether the bits sent are received correctly. Bit Error Rate (or Ratio, as it is more correctly called) measures this performance, and BERTs are a common feature in many test labs either as BER measuring devices, or as test pattern sources for other measurements. (SR-TN034)   Download PDF - 90 kB

Anatomy of an Eye Diagram — A Primer • OCT 2004       Abstract + This paper describes what an eye diagram is, how it is constructed and common methods of triggering used to generate one. It then describes different ways that information from an eye diagram can be sliced to gain more insight. It also discusses some basic ways that transmitters, channels and receivers are tested. It is designed to give an engineer new to this field a basic grasp of the concepts commonly used. (SR-TN033) See related poster below   Download PDF - 0.5 MB

Anatomy of an Eye Diagram poster • Guy Foster • OCT 2004       Abstract + Our colorful, informative posters introduce basic principles and applications of foundational techniques in signal integrity testing. They are about testing digital high speed communications electronics, and are intended for electronics engineers who need to verify compliance of their products. The poster is approximately 27” x 38” (68.5 x 96.5 cm), printed in full color on glossy, heavyweight paper. Eye diagrams are a very successful way of quickly and intuitively addressing the quality of a digital signal. A properly constructed eye … often shows weaknesses in system design… (SR-TN035) See related white paper above   Request the poster

A new signal integrity test and measurement architecture for serial 10 Gb/s interfaces • Tom Lindsay • OCT 2004       Abstract + New high-speed serial communications specifications such as 10G Ethernet and OIF’s CEI create challenging demands for signal integrity test and analysis. A novel dual-sampler Bit Error Rate test (BERT) architecture addresses these needs by integrating eye diagram, eye mask, jitter, Q-factor, BER, and other physical layer measurements into a single instrument. This paper shows actual results of how these physical layer tests can be done with far greater speed and statistical accuracy and confidence than previously possible. (SR-TN036)   Download PDF - 1.8 MB

Bridging the Gap between BER and Eye Diagrams — A BER Contour Tutorial • OCT 2004       Abstract + This paper provides an introduction to the BER Contour measurement - what it is, how it is constructed, and why it is a valuable way of viewing parametric performance at gigabit speeds. It also provides illustrative examples of BER Contour in action, taken with a SyntheSys Research BERTScope 12500A 12.5 Gb/s Signal Integrity Analyzer. (SR-TN032)   Download PDF - 0.9 MB

"High-Speed Digital Test of XFP MSA Modules" • article published in LIGHTWAVE • Charlie Schaffer • MAR 2004       Abstract + The XFP/XFI Transceiver MSA (multi-source agreement) has developed significant momentum in the telecommunications and datacommunications industry. Many transceiver manufacturers, including Bookham, JDSU, Agilent Technologies, Finisar, MergeOptics, Intel, Infineon, Opnext, Picolight, and Sumitomo Electric, have announced XFP modules and a number of communications IC vendors having announced devices in support of the standard. Perhaps most important, at least one key equipment manufacturer, Cisco, has committed to the new interface. Unlike the other 10 Gb MSAs, the XFP transceivers feature a 10 Gb/s differential I/O interface—XFI  “ziffy”— instead of a 16-channel SERDES found in the 300-pin MSA and 4-channel Xaui in Xenpacks, Xpaks, and X2. Though the other MSAs will doubtless continue to be used for some time, many in the industry expect XFP to become the dominant 10 Gb optical interface for applications other than DWDM and long haul transport. (SR-TN031)   Download PDF - 0.5 MB   Article reproduction (not printable) - 120 kB     Read article at LIGHTWAVE

2003

Using Bit Error Rate Testers to Drive Forward Error Correction Codes • Tom Waschura • SEPT 2003       Abstract + Forward Error Correction is a critical component in many modern digital communications applications, turning otherwise unusable communications links into real and practical systems.   From DVDs to cell phones, satellite TV to disk drives, error correction technology is a mathematical marvel that effectively makes a silk purse from a sow’s ear. (SR-TN029)   Download PDF - 0.4 MB

Innovations in BER testers enable fast and accurate eye diagram, eye mask, Q-factor, and jitter measurements • Tom Lindsay • SEPT 2003       Abstract + Successful integration of fast and accurate eye diagram, eye mask, jitter, and Q-factor functions into a BERT has been demonstrated. These measurements can be done with far greater speed and statistical accuracy than previously possible. • ©2003 Optical Society of America • OCTS codes:(120.4800) Optical standards and testing; (060.2330) Fiber optics communications (SR-TN030)   Download PDF - 0.4 MB

2002

BER Testing for SFI-4 Applications • Jim Dunford • MAY 2002       Abstract + Manufacturers and integrators of optical networking modules have worked together to specify mechanical and electrical interfaces in order to promote module-to-module interoperability. One such agreement is the SFI-4 standard for the OC-192 framer-to-SERDES interface developed by the Optical Internetworking Forum. This white paper provides background on the SFI-4 interface and presents a means for characterization of Bit Error Rate performance of transceiver systems at the SFI-4, and other similar interfaces. (SR-TN014)   Download PDF - 0.3 MB

2001

Testing Applications in Uncompressed HDTV Signals • Jim Waschura • NOV 2001       Abstract + This paper focuses on testing methods and applications for the uncompressed HDTV signal, SMPTE 292M. It includes a description of the signal's electrical characteristics, digital format, and special protocols for embedding auxiliary information. This is followed by an explanation of testing methodologies and tools used to verify compliance to the SMPTE specification. Afterwards, the author suggests two specific areas for automatic testing in the product manufacturing cycle: design verification and manufacturing test. (SR-TN023)   Download PDF - 0.5 MB

SDI Testing — A Toolbox at Your Fingertips • Jim Waschura • NOV 2001       Abstract + Yes, we've all heard it: "Digital is perfect; why would I want to test it?" And largely, this sentiment reflects the reality of many off-line or noncritical video system installations. At installations that are time-critical, however, like live production and broadcasting, engineers know that being able to quickly diagnose a problem can help them to make repairs rapidly and save on equipment and personnel downtime. In addition, engineers involved in system installation and maintenance are aware that compatibility between system components and signal quality are the two most important indicators of system robustness. Of course, the developers of video systems know that evaluating quality of their systems before shipping translates to a higher "out of the box" success rate, which means more customer satisfaction and repeat business. (SR-TN022)   Download PDF - 0.3 MB

Bit Error Location Analysis for Instrumentation Recording Applications • NOV 2001       Abstract + This paper describes techniques for error location analysis used in the design and testing of high-speed instrumentation data recording and communications applications. It focuses on the differences between common bit error rate testing and new error location analysis. Examples of techniques presented include separating bit and burst error components, studying probability of burst occurrences, looking at error free interval occurrence rates as well as auto-correlating error position. Each technique contributes to a better understanding of the underlying error phenomenon and enables higher-quality digital recording and communication. Specific applications in error correction coding emulation, magnetic media error mapping, and systematic error interference are discussed. (SR-TN024)   Download PDF - 0.2 MB

Application Note: Error Correction Coding Emulation • SEPT 2001       Abstract + ID1-type tape recorders are widely used in industry today. This type of recorder uses eight helical scanning heads to sequentially read data off magnetic tape. Each head reads a track length of 36,108 user-data bytes (288,864 bits) recorded on the tape at a 5-degree angle. When data is recorded to an ID1-type tape, it is interleaved according to the ID1 standard. Likewise, data scanned from these tapes is passed through three-dimensional Reed-Solomon Error Correction Coding, which corrects and de-interleaves the data back into user format. In analysis of ID1 error data, it is most useful to re-interleave the output data back into the tape format for error measurement and analysis purposes. This is easily accomplished through the use of the BitAlyzer ECC option. The paper describes hardware interfacing, ID1 interleaving, ID1 de-interleaving, and BitAlyzer re-interleaving. Several analysis examples are included as well. (SR-TN027)   Download PDF - 0.4 MB

2000

Error Location Analysis Tutorial • MAY 2000       Abstract + Bit error rate testing has always been a useful development tool. In most cases, however, a simple bit error rate does little—if anything—to identify the sources of errors. For that, you need error location analysis. The patented error location analysis methods used in SyntheSys Research's BERTScopes and BitAlyzers offer you the opportunity to study your bit errors in detail, helping you find relationships that uncover the cause behind errors. Here is how to learn more about what error location analysis is and how different types of analysis can be used under various conditions.   View online

Bit Error Analysis and Beyond • MAR 2000       Abstract + In the past, bit error rate testing meant transmitting a pseudo-random sequence of bits through a channel under test and counting the number of incorrectly received bits at the receiving end. This technique was adequate because the basic question to be answered was, "is it working?" Today's communication systems are pushing the envelope further and further, trying to squeeze as much bandwidth out of a channel as possible, and the question has now become, "How can I make it work better?" Forward error correction, data compression, and sophisticated modulation codes are some examples of these techniques. In these systems, knowing the position of an error relative to the data being transmitted or relative to other errors, is crucial in order to optimize the efficiency of a given technique. This class discusses many techniques for bit-accurate analysis, and discusses the concept of an overall system error budget. (SR-TN015)   Download PDF - 0.3 MB

1998

Digital Channel Error Correction Coding Design Tools • 1998       Abstract + Error correction coding theory describes ways to add overhead to transmitted or stored messages to insure that they can be understood when received or played back. Challenging implementations of error correction coding theory are responsible for many advances in digital communications applications ranging from deep space exploration to high-density disk drives, cellular telephones and pager networks. (SR-TN012)