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TopCAT automation and productivity enhancements highlight new ScanWorks 3.3.2

A new productivity technology has been incorporated into ScanWorks, markedly decreasing the time it takes to automatically generate tests. Known as TopCAT™ (Topology and Cluster Analysis Technology), the new technology dramatically reduces the time to achieve an acceptable level of test coverage. For example, benchmark tests using TopCAT on a complex router board with almost 9,000 nets, over 40,000 solder joints, approximately 6,000 components including more than 60 memory clusters and over 40 logic clusters reduced test development time to less than a day and ensured high test coverage.

In addition to TopCAT, the new ScanWorks Version 3.2.2, which will be available during the fourth quarter of 2003, has a higher level of automation for generating manufacturing test programs, productivity enhancements for diagnosis and repair applications, new hardware modules that increase test coverage and throughput, and features which makes it easier to integrate ScanWorks into test executive environments.

What's TopCAT

The first thing TopCAT does is analyze a design schematic to identify the non-boundary scan devices that are connected to boundary scan devices. These non-boundary scan devices are candidates for boundary scan cluster tests. TopCAT then automatically matches the names of non-boundary scan devices in the netlist with device models which are archived on ASSET's web site or are often available within the user organization. The final step for TopCAT is to optimize the configuration of the device models for the highest test coverage and to ensure the safety of the board. Because TopCAT-generated tests achieve much higher test coverage on first-pass test generation, a design's overall test strategy can be developed much faster.

TopCAT technology has been applied to all of the ScanWorks automatic test generators, including scan path testing, interconnect testing and memory access verification (MAV).

TopCAT's Model Matching

A major productivity enhancement comes from TopCAT's ability to automatically match the non-boundary-scan device-type names that are used during schematic capture to the appropriate cluster model. After finding a match, TopCAT automatically associates the cluster model with an interconnect action as the test action is built. Because of TopCAT's ability to match a device type name, which is required by most organizations' automated design procedures, with a generic model in a ScanWorks library, the only cluster models that must be assigned to device type names are those that are new to the model library.

Optimizing Model Configurations

By automatically determining the most effective way to treat a device during test, ScanWorks with TopCAT automatically configures the model to ensure the highest test coverage and safe test execution. For example, a “244” buffer device can operate with all outputs enabled, all outputs disabled or some enabled and some disabled. Assuming boundary-scan access to the enable signals, TopCAT uses model information to enable the appropriate configuration of the 244 buffer to allow boundary-scan testing through the buffer. ScanWorks can test through any number of buffers/resistors in series. ScanWorks also makes sure that enabling a buffer does not cause contention problems on either that net or any other net driven by a buffer enabled by the same signal.

     Figure 1 Cluster Example

TopCAT's Impact on Memory Access Verification (MAV) Automation

Many large designs include several different memory arrays, each with different types of memory devices. This means that many individual MAV actions could be required to test the access to all of the memory devices in the design. With TopCAT for ScanWorks, the generation of memory access verification (MAV) tests can be accelerated considerably.

For example, by simply clicking on the new "Auto-Create" function button in ScanWorks, TopCAT technology automatically locates all instances of a device type and creates a MAV action for each one. Another new function called “Replicate” analyzes a design to find all instances of a device type used in a specific action. It then creates a separate test action with the same parameters as the original action each time it finds that particular device.

Enhancing the Productivity of Manufacturing Test

Designs with more than 10,000 nets can require a large number of ScanWorks actions to provide adequate test coverage and programming operations. Also, large designs are often available in several configurations, requiring several similar but slightly different sequences for manufacturing test. Creating these sequences by adding all the actions to a sequence and setting the flow control options for each one can be time consuming.

Now, ScanWorks 3.3.2 can automatically incorporate all currently available actions into any new sequence. The actions in the new sequence are arranged in a predefined order and predefined settings for flow control are automatically inserted. Once the basic sequence is created, it can be customized for the specific application with the easy-to-use sequence editor.

In addition, sequences can now be copied or cloned in ScanWorks 3.3.2. Sequences that are copied are re-named, but they reference the same design description as the original sequence. Copying and editing sequences means that multiple sequences can be quickly created with slight variations from the original. Cloned sequences are given a new and unique name, but they reference a different design description from the original sequence. Some designs require several variations of a basic design. Each variation of the base design usually requires the same test actions and sequences as the original. By cloning a sequence, a new sequence can be quickly duplicated and altered slightly from the original base design.

Another feature that simplifies the handling of sequences for prototype debugging or board repair operations is the ability of ScanWorks 3.3.2 to enable the user to select only one or several actions within a sequence to run. This can save significant troubleshooting time when only one action has failed. Rather than run all of the actions which make up a sequence, including time-consuming actions like PLD programming operations, the user can specify the actions to execute during troubleshooting and observe the results.

New Hardware Options

Besides the software capabilities that improve user productivity, ScanWorks 3.3.2 has expanded hardware alternatives that tailor ScanWorks to the specific needs of most applications. For example, with the new PXI-100 controller card, the flexibility of ScanWorks is expanded by enabling a ScanWorks deployment in a 3U PXI or CompactPCI chassis.

The PXI-100 simplifies the implementation of ScanWorks in functional test operations where PXI-based platforms are frequently found. The seamless integration of ScanWorks under tools such as National Instruments' TestStand™, LabVIEW® and LabWindows/CVI®, as well as Agilent Technologies' Visual Engineering Environment (VEE) and Visual Basic makes a PXI-based test platform more productive and reduces test costs because ScanWorks' extensive test and diagnostic capabilities can be employed on the same platform where functional tests and analog measurements are being performed.

As many as eight single TAP controller cards, either the PXI-100 or the PCI-100, can be deployed at the same time in a single PXI card cage or PCI-based PC.

In addition to supporting the PXI-100 controller, ScanWorks 3.3.2 also offers several other new hardware options, including the Multitap Buffer Board and the Boundary Scan 400 IO Module.

The Multitap Buffer Board is a cost-effective means of connecting a ScanWorks PCI-100 controller to as many as four scan paths on a board. By connecting to multiple scan paths simultaneously, ScanWorks can create and apply tests or programming operations to the combined scan paths, increasing test coverage for the board or system. The Multitap Buffer Board is intended to be built into a fixture.

The Boundary Scan 400 IO Module provides 400 test channels to expand boundary scan test coverage between connectors and on-board boundary-scan devices.

The 3.3.2 version of ScanWorks certainly contains many new hardware and software capabilities that enhance the productivity of an organization's test and in-system programming processes. For more information on ScanWorks, click here.