The Newsletter

An A.T.E. Solutions, Inc. Internet Publication
Volume 11 Number 2 January 16, 2007

The Testability Director Version 3.2

Reach the thousands of test professionals we mail to. Sponsor The BestTest Newsletter and we will place your logo here.

Visit BestTest - A Test Community Web Site
Test Vendor Directory
Products/Services Directory
Test Dictionary
Test Events
Test Publications

Test related books
Test/Testability Software

How We Can Help
Test Requirements Analysis
Test Related Courses
ATE and Test Market Help
Design for Testability
Built-In Self Test

Links Worth a Click
Test sites of interest:

Cable Test Systems, Inc.
Chroma USA
Evaluation Engineering
International Test Conference
IPC - APEX Conference Organizers
Powell-Mucha Consulting, Inc.
Test & Measurement World

Want to trade links? We'll list yours here and you list ours at your site.
Test Vendors
We now have 2274 test vendors listed in the Test Vendor Directory. Check for accuracy.
The following companies have recently placed advertising with us:
A.H. Systems, Inc.
A.T.E. Solutions, Inc.
Capital Equipment Corp.
CEIBIS Cody Electronics
ESPEC North America
FTS Systems, Inc.
Ground Zero ElectroStatics
Intellitech Corporation
Invisar, Inc.
JTAG Technologies, Inc.
Madell Technology Corporation
Measurement Computing
Pickering Interfaces, Ltd.
ProbeStar, Inc.
QStar BE
Tabor Electronics
Tecpel Co., Ltd.
Teradyne Assembly Test Division
Tiepie Engineering
VI Technology, Inc.
Wavecrest Corp.
WesTest Engineering Corp.
Yokogawa Corp. of America
Z World
A.T.E. Solutions, Inc.
   Consulting Services
   Consulting, Training and Books
   The Testability Director
   The Testability Director 3.2
Auriga Measurement Systems, LLC
   Microwave/Millimeter Wave Test Systems
Capital Equipment Corporation
Flynn Systems Corp.
   onTAP® Boundary Scan Software
Geotest Inc.
GOEPEL electronic GmbH
   OptiCon BasicLine
   SCANPLUS Board Grabber
ICS Electronics
Intellitech Corp.
   PT100 Parallel Tester
   PT100 Rack
   Scan-Ring-Linker & multi-PCB linker
JTAG Technologies, Inc.
   JT 3710/PXI
   JT 37x7 DataBlaster boundary-scan controllers
Meret Optical Communications
   ADS 53x DDS Synthesizer
Norvada, LLC
Professional Testing DBA Pro Test
   Environmental Testing
Quad Tech
   Guardian 1030S Multi-Purpose AC/DC/IR/SC Hipot Tes
Quantum Change, Inc.
   The TILE EMC Software
Reinhardt System und Messelectronic
   ATS-KMFT 670
Ricreations, Inc
   CleverScope CS328
   USB Explorer 200
   SMX2040 series
Static Solutions
   CT-8900 Combination Data Logger Tester
Symtx, Inc.
SyntheSys Research, Inc.
   BERTScope™ 12500A
Tabor Electronics
   Model 5200 Arbitrary Waveform Generator
   Test Equipment
TestEdge, Inc.
Testpro AS
   TP2101 Testsystem
The Test Connection Inc.
   In-Ciruit Test & Flying Probe Test
UltraTest International
Universal Synaptics
   Vanguard Express
WesTest Engineering
WesTest Engineering Corp.
   WesTest 2000
YESTech Inc.
   YTV series of AOI
Yokogawa Corp. of America
This Issue's Feature Articles

The State of Memory Testing


Scott LaRoche, Sales Director, Innoventions, Inc. 

IEEE P1581 Offers Solutions for Board Level Memory Test Problems

By: Heiko Ehrenberg, GOEPEL Electronics USA

User Instruction

You will be linked directly to the listings you select below after you have  logged in. If you are not logged in, go to 

Product/Service Focus

This issue's focus is Memory Testing
You can view and add to our existing list of Test Products/Services, Test Literature, Test Definitions, Test Vendors, containing "GPIB"

What's New in Test
  1/15/2007 GOEPEL electronic’s AOI System OptiCon BasicLine wins “Best in Test Award”
  1/12/2007 SystemBIST receives honorable mention in “Best in Test” for 2007
  1/10/2007 Agilent to demonstrate its communications testing solutions at 3GSM 2007
  1/10/2007 JTAG Technologies Wins Best-in-Test(R) Award for TapCommunicator(TM)

Come to the tutorial

Cost Effective Tests Using ATE, DFT and BIST

by Louis Y. Ungar at APEX on February 18, 2007 

  1/9/2007 ASE Test, Inc. posts dismal December revenues
  1/9/2007 GOEPEL electronics to run first Boundary Scan Day in UK
  1/8/2007 Aptix founder sentenced to 17 years for perjury, obstruction of justice
  1/8/2007 EU regulators clear Motorola purchase of Symbol
  1/8/2007 KLA buys Therma-Wave in $75M deal
  1/8/2007 Lack of radio spectrum could hamper RFID success
  1/5/2007 Engineering Education Gets Its Own Reality TV Show
  1/4/2007 Court orders Magma to withdraw 2 patent claims in Synopsys suit
  1/3/2007 Hardware-assisted verification market boosted with EVE’s Tharas buy
  1/2/2007 MTCS Systems Engineering and CableTest Systems Form Alliance
FREE Giveaways

Visit A.T.E. Solutions, Inc. on January 22-26, 2007 at 
Measurement Science Conference - Booth #444 

and win an iPod

  1/10/2007 Request Your Copy of Keithley's 2007 Product Catalog
Magazine Articles
  1/11/2007 R&D In T&M Leads To New I&T—Innovation & Technology
  1/9/2007 Guest commentary: IJTAG, SJTAG claims premature
  1/4/2007 Testing our reliance on testing: Worst-case scenarios in mixed-signal design
  1/4/2007 Unwrapping wireless signals - Arbitrary Waveform Generators
  1/1/2007 ‘Design-with-test’ for low-power devices
  1/1/2007 Another One Rides the Bus - Selecting the right bus
  1/1/2007 EMC Effects from the Hidden Schematic
  1/1/2007 Evaluation Engineering Reader Choice 2006
  1/1/2007 How Best to Measure Spread Spectrum Clocking (SSC) on Data
  1/1/2007 IEEE Design & Test of Computers - 2006 Annual Index
  1/1/2007 Taking a Signal to Bits - Jitter Analysis
  1/1/2007 Vanishing Point - EMC Shielding
  1/1/2007 Vibration Testing Shakes Things Up
Product Releases
  1/16/2007 Microwave testers offer broadband capability
  1/16/2007 Test platform supports entire A-GPS devt cycle
  1/11/2007 Are your board designs testable? -TestWay
  1/11/2007 Remote & Local Continuity Tester
  1/11/2007 XYZ-axis accelerometers roll for mobile CE apps
  1/10/2007 Data Device Corp. announces MIL-STD-1553 PCI-104 card
  1/9/2007 Verilog simulator offers faster RTL, gate-level simulation
  1/8/2007 Agilent Technologies Introduces J-BERT Functionality that Enables Industry's Fastest Jitter Tolerance Test Results
  1/4/2007 Handheld spectrum analyzer reaches 20 GHz
  1/3/2007 Board eases devt, testing of DSP algorithms
  1/3/2007 New Automated X-ray Inspection Capabilities with Latest Software Release
  1/3/2007 Testing solutions roll for RF conducted immunity
  1/2/2007 Enhancement Enables Live Data-Connection Setup with Full Network Emulation
  1/1/2007 Software tests products' compliance with eight popular, high-speed serial protocols
  1/9/2007 "Fear and cost savings" motivate Sarbanes-Oxley compliance, study says
  1/8/2007 Consumer Electronics Assoc. forecasts $155B in consumer electronics revenue
  1/8/2007 U.S. economy in midst of slowdown
  1/4/2007 IPC-TM-650 Test Methods
The State of Memory Testing
Scott LaRoche, Sales Director, Innoventions, Inc.

An ancient philosopher once said, "The only constant is change." The computer memory industry is certainly no different. Since we wrote an article about memory testing for the Best Test Newsletter (see “How to Select a Memory Tester”, August 16, 2004), computer memory has become even more complex, with greater size and faster operating speeds. These changes make testing memory before installation even more critical.

The most important change is the switch from DDR SDRAM (Double Data Rate Synchronous Dynamic Random Access Memory - you can see why the industry simply refers to it as DDR!) to DDR2 SDRAM. In a nutshell, DDR2 is capable of running at a much higher frequency and lower power than DDR. In our prior article we wrote, “Windows XP computers are typically shipping with memory modules operating at 333 MHz or faster.” Two years later, common DDR2 modules operate at twice the bus speed of older DDR technology, which substantially improves overall computer performance.

However, DDR2 memory modules capable of running at 667 MHz and 800 MHz have issues not seen in older DDR modules. Individual DDR2 chips come in BGA (Ball Grid Array) packages while DDR chips are usually the TSOP (Thin Small Outline Package) format. BGA requires a far more complex soldering process during the manufacturing stage than older TSOP packages, which means that more stringent testing is required to spot memory faults. Aluminum spreaders are commonly mounted on DDR2 modules since the higher frequencies generate a great deal of heat, although DDR2 uses smaller page sizes than DDR1 to reduce power. DDR2 also operates at a lower operating voltage than older DDR1 designs and require more control circuitry. These traits make DDR2 far more complex, and while DDR2 isn’t necessarily more prone to failure than older memory formats, more stringent testing is required in order to weed out defective memory.

The second change is the upcoming consumer release of Vista, Microsoft’s new Windows operating system. Consumer reviews have been mostly positive, but all reviewers agree that Vista is a “memory hog” that requires at least 1 GB of main memory in order to run efficiently. This means that an average PC running Vista will require at least twice the memory of a PC running Windows XP. This is obviously good news for the memory industry eager to sell more product! But larger 1 GB and 2GB modules (up from 256 MB and 512 MB just 2 years ago) demand more exhaustive testing since the increase in cells and the more complex wiring also increases the chance for faults.

Computer techs have a number of free tools at their disposal to test DDR2 modules, such as the Windows Memory Diagnostic software available from Microsoft. It allows you to test memory directly on a motherboard by booting up the software via floppy disk or CD.

While testing memory directly on a motherboard may be a good solution for some, it is not an acceptable solution for those who need to regularly test memory. Testing via the motherboard frequently takes hours per stick of memory and the motherboard socket is not made for constant insertion/removal. If you break the socket, you’ve severely damaged the motherboard!

Fortunately, dedicated memory testers are available for quickly testing large volumes of memory. Such dedicated testers range in price from less than $1,000 to over $1 million. On the simplest level, such testers use complex algorithms to check for problems such as shorts in the wiring and cell interference.  They also run tests at different voltage levels and frequencies. More expensive testers are used for exhaustive testing, and include increasingly complex test algorithms and even temperature stress chambers.

Small, low-cost standalone testers are sufficient for most users and catch the vast majority of faults. (See RAMCHECK DDR2 for an example.) Their low cost means that manufacturers, dealers and data centers can acquire a number of testers and spread them throughout each facility. However, it is important to note that low-cost testers are not meant to be used as certifying testers! Memory used in mission-critical sectors such as defense and aerospace, or testing done during the early stages of the manufacturing process, must use high-end test equipment made specifically for this purpose. Since testers can be major investments, it is important to make sure the unit is upgradeable and expandable. The tester vendor should provide frequent firmware upgrades and “swappable” adapters to extend the life of the tester beyond just the current memory types.

New memory technology is on the horizon, making it likely that even more complex testing will be required. DDR3 will be appearing on the market within a year or so. But what will follow DDR3? There are no guarantees - except change - but the odds favor increasingly complex memory that requires even more stringent testing.

IEEE P1581 Offers Solutions for Board Level Memory Test Problems

 Heiko Ehrenberg, GOEPEL Electronics USA

To be competitive in today's world market, electronics manufacturers are pressured to produce more products of better quality in shorter time for lower cost. To achieve this goal, all manufacturing stages have to be optimized, including test. To keep the cost of test and the cost of repair low, reliable and guaranteed detection and localization of structural faults at board and system level in the shortest possible time is top priority. This includes all circuitry on the Unit Under Test, including connections to memory devices.

Testing connectivity to memory devices in functional test may not be possible or may not yield the needed diagnostic resolution. The development of functional test software is very time consuming and therefore costly, especially when good diagnostics are a requirement. Furthermore, if a board or system does not boot up, functional tests cannot be executed at all.

The only other option to electrically test memory device connectivity at pin level is through In-Circuit Test or - if access from an In-Circuit Test fixture is not available - through IEEE-Std.1149.1/Boundary Scan. Both also have limitations that need to be overcome in order for board and system level test technology to keep up with the ever increasing complexity of memory devices.

Memory device manufacturers in general have steadily resisted implementing IEEE-Std. 1149.1 in their devices. The IEEE P1581 working group is defining a new standard for static component interconnection test, dramatically simplifying the test of memory interconnects. With the defined test architecture embedded in memory devices, the memory cell structure is completely bypassed; a simple, combinatorial test circuitry implemented into the memory device is used instead to link input and output signals during test mode. A controlling device (typically an IEEE 1149.1 compliant component connected to the memory device) applies a stimulus to the input pins and observes the output pins of the device under test. The benefits of this methodology, which eliminates the need for functional memory access cycles during memory connectivity tests, include very simple test pattern, few test vectors, very short test execution time, full diagnostic capability for structural faults, and a simple Design for Testability implementation in the device under test.

Memory Cluster Testing with Boundary Scan access

Today, Boundary Scan connectivity test at board and system level frequently includes memory devices (typically referred to as Memory Cluster Test). Even though such memory devices often times don't have IEEE 1149.1 resources built-in, connectivity to them can be tested by using 1149.1 access to their address, data, and control signals from the controlling device (e.g. a CPU, FPGA, DSP, or ASIC).

Traditional memory cluster test at board and system level is based on functional device models. These models describe the pin functionality as well as the write, read, and other access cycles for a particular memory device. The host/master component connected to the memory device uses the model to write test pattern to the memory and then to read back that pattern, in an attempt to detect and diagnose any structural faults on the memory pins (opens, shorts, stuck-at-0/1). Typically, a "walking 1" and "walking 0" pattern set is written to the address signals, a walking data pattern is written using a counting address pattern, and so on, and the data is read back from the memory to verify the write operations. If the correct data is read back, access to the memory appears to be without failures. If not, the data actually read can provide diagnostic information about the defect (the actual test pattern depends on the ATPG software, which uses CAD information to automatically generate the test).

Introducing IEEE P1581

In an attempt to overcome problems with memory cluster test based on functional device models, the IEEE P1581 working group is defining a protocol and architecture for static component interconnection test. This standard is being developed to define a test strategy to be implemented in complex memory devices which do not support IEEE 1149.1. It describes a simple means to verify the memory I/O pin connectivity (address, data, and control signals). In a test mode operation, the memory cell structure is completely bypassed; a combinatorial test circuitry implemented into the memory device is used instead to link input and output signals. The control of whether the device is to be tested or in normal operation is accomplished with either some Test Mode Control logic or with an optional Test Pin as defined in the IEEE P1581 proposal (for details regarding Test Mode Entry and Exit, as well as the actual test logic implemented in a P1581 compliant device, please contact the working group). A controlling device (typically an IEEE 1149.1 compliant component connected to the memory device) applies a stimulus to the input pins and observes the output pins of the device under test.

The Combinatorial Test Logic embedded into a P1581 compliant device consists of a simple XOR/XNOR structure or Inverters and other logic gates, linking memory input pins to output pins so that each output is connected through the test logic to a unique set of inputs. One of the most important aspects of the P1581 architecture is that a connection error on one of the pins will not inhibit the test of other pins.

For more information on Memory Cluster Test or to request a white paper on IEEE P1581, please contact the working group  or write to

Next Issue's Product/Service Focus
In our next issue of Product/Service Focus we will cover Sensors. You can add or upgrade a listing before the next issue comes out.

If you would like to include an exclusive article on how to best select Sensors, please contact

  • If your friend forwarded this newsletter to you, please register as a member and receive The BestTest Newsletter -- absolutely free!
  • If you wish to update your news preferences or cancel the subscription, please unsubscribe.
  • If you have any questions, please email
See an Index of Past and Upcoming Issues of The BestTest Newsletter

Email The BestTest Newsletter to a Friend whose email is
Online Bookstore

Get the widest selection of test related books and software at the BestTest Online Store.

Find any text on test. Search the topic below:

Search Now:

Reach the thousands of test professionals we mail to.
Place Ad here.


1/22 - 1/26
   Measurement Science Conference
2/5 - 2/8
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
   Cost Effective Tests Using ATE, DFT and BIST
3/6 - 3/8
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
9/17 - 9/21
   AutoTestCon 2007
1/17 - 1/19
1/22 - 1/25
   The Annual Reliability and Maintainability Symposium (RAMS)
1/22 - 1/25
   Medalist Bead Probe Technology Webcast
   Agilent Medalist Bead Probe Technology - A Simple and Proven Test Solution for Limited Access PCBs
1/29 - 2/1
   DesignCon 2007
1/30 - 2/1
   Pan Pacific Microelectronics Symposium
2/6 - 2/8
2/12 - 2/15
   3GSM 2007 World Congress
2/20 - 2/27
   APEX/IPC Printed Circuits Expo
2/24 - 2/27
   Electrical Safety and Reliability Conference
2/25 - 3/1
   Applied Power Electronics Conference (APEC)
2/27 - 3/2
   Expo Comm Mexico
   Boundary Scan Day UK
3/5 - 3/7
   International Test Synthesis Workshop (ITSW 2007)
3/11 - 3/14
   IEEE Latin-American Test Workshop (LATW 2007)
3/21 - 3/23
   Electronica and Productronica China
4/1 - 4/5
   Embedded Systems Conference
4/4 - 4/6
4/10 - 4/12
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
4/11 - 4/13
   IEEE Workshop on Design and Diagnostics of Electronic Circuits and Systems (DDECS 2007)
4/15 - 4/19
   International Reliability Physics Symposium
4/16 - 4/20
   International Conference on Data Engineering (ICDE 2007)
4/16 - 4/20
   Design Automation and Test in Europe (DATE)
   Diagnostic Services in Network-on-Chips
4/24 - 4/27
   Nepcon China 2007
4/30 - 5/3
   International Instrumentation Symposium
5/6 - 5/10
5/8 - 5/10
   Automotive Testing Expo Europe
5/10 - 5/11
   IEEE International Workshop on Open Source Test Technology Tools
5/15 - 5/17
5/20 - 5/24
   12th IEEE European Test Symposium (ETS'07)
5/24 - 5/25
   European Board Test Workshop (EBTW)
6/4 - 6/8
   44th Design Automation Conference
6/12 - 6/14
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
6/19 - 6/22
   Nepcon Malaysia
6/20 - 6/22
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
6/20 - 6/21
   Successful Lead-Free RoHS Strategies Conference – Do it Right, Do it Now
6/21 - 6/24
   Nepcon Thailand
7/10 - 7/12
   Fundamentals of Random Vibration and Shock Testing, HALT, ESS, HASS
8/28 - 8/31
   NEPCON South China
9/21 - 9/23
   IEEE Wireless Communications, Networking and Mobile Computing (WiCOM2007)
10/7 - 10/11
   SMTA International 2007
11/6 - 11/8
   Bohai Electronics Week
New Definitions
New terms added to the Test Definition section:
Burst Immunity Test
Clock Data and Recovery
Conducted Immunity Test
Conformance Testing
Electrostatic discharge (ESD) Immunity Test
Powerline Dip Immunity Test
Powerline Surge Immunity Test
Radiated Emissions Test
Radiated Immunity Test
Sarbanes-Oxley Act
Spread Spectrum Clocking
Time Interval Error
Wraparound Artifacts
We now have 2313 test terms in our Test Definition section.

Share your definitions with the test community.