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Packetized Scan Test Delivery


The traditional approach to moving scan test data from chip-level pins to core-level scan channels is under pressure due to the dramatic rise in design size, design complexity, and test adaptation. To address these challenges, we now have the option of implementing a packetized data network for scan test that moves the scan data through the SoC much more efficiently than the traditional pin-... » read more

Have It All With No-Compromise DFT


The dramatic rise in manufacturing test time for today’s large and complex SoCs is rooted in the use of traditional approaches to moving scan test data from chip-level pins to core-level scan channels. The pin-multiplexing (mux) approach works fine for smaller designs but can become problematic with an increase in the number of cores and the design complexity on today’s SoCs. The next revol... » read more

Digital Test Bulks Up – Or Down


Large digital integrated circuits are becoming harder to test in a time- and cost-efficient manner. AI chips, in particular, have tiled architectures that are putting pressure on older testing strategies due to the volume of test vectors required. In some cases, these chips are so large that they exceed reticle size, requiring them to be stitched together. New testing efficiencies are needed... » read more

Making IC Test Faster And More Accessible: Part 2


Recently, my colleague Robert Ruiz described a new approach to scan test that utilizes the high-speed I/O (HSIO) ports that exist on most chips. The benefits of this new approach include reduced test time and cost thanks to the high-speed interface. Simplified pin electronics and tester setup are also benefits, as is the ability to run manufacturing tests in the field in support of silicon life... » read more

Making IC Test Faster And More Accessible: Part 1


The fundamental challenges of IC test have been the same for a long time. At the heart of all test strategies is controllability and observability. First, control the state of the chip with known test vectors and then observe the chip to determine if it exhibits good or faulty behavior. There have been many innovations over the years to make the required testing of chips more tractable. Thanks ... » read more

Scan Diagnosis


Jayant D’Souza, product manager at Mentor, a Siemens Business, explains the difference between scan test and scan diagnosis, what causes values in a scan test to change, how this can be used to hone in on the actual cause of a failure in a design, and how to utilize test hardware more efficiently. » read more

The Single Best DFT Move You Can Make


A proven method to simplify a complex problem is to break it into smaller chunks. In the case of today’s large, complex SoCs, this means using hierarchical methods to design the blocks, then combine the results at the top level. While this sounds obvious, it hasn’t always been practical or technologically feasible to perform some tasks, like DFT, at the block level and translate that work s... » read more

Scan Compression Is No Longer About Compression


Scan compression was introduced in the year 2000 and has seen rapid adoption. Nearly every design’s test methodology today implements this technology, which inserts compression logic in the scan path between the scan I/Os and the internal chains. In this article, we take a critical look at the technology to understand how scan compression has matured. The road to scan compression Since th... » read more

Highly Efficient Scan Diagnosis With Dynamic Partitioning


Charged with the task of improving yield, product engineers need to find the location of defects in manufactured ICs quickly and efficiently. Typically, they use volume scan diagnosis to generate large amounts of data from failing test cycles, which is then analyzed to reveal the location of defects. Scan failure data provides the basis for many decisions in the failure analysis and yield impro... » read more

Breakthrough For Scan Diagnosis With Machine Learning


Cell-aware diagnosis is a new and effective way to detect defects inside standard cells. Industry standard failure analysis (FA) results from a major foundry show that cell-aware diagnosis is very effective at increasing the resolution of the diagnosis by reducing the number of suspects in cell-internal defect data. With advanced technology nodes, we have more complex layout structures and f... » read more

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