Embedded instruments

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Peruse this year's “Best in Test” products, and you'll see test-related software as well as oscilloscopes, analyzers, and multimeters. The software that inserts testability structures into designs and that helps analyze test results to improve yield will become increasingly important as traditional instruments lose access to circuit nodes buried within deep-submicron ICs, multichip packages, and BGA-populated printed-circuit boards (PCBs).

Addressing PCBs, Asset InterTech at the International Test Conference (ITC) announced that it has expanded its embedded-instrument support by adding signal-integrity analysis to its Intel IBIST (interconnect built-in self-test) functionality. Tim Caffee, Asset's VP for design validation, said IBIST-based embedded instrumentation is critical for handling dramatically increased data-transfer speeds on PCBs with dramatically diminished physical-test-probe access. Asset recently augmented its embedded instrument technology with the acquisition of International Test Technologies (See our article Asset InterTech acquires International Test Technologies), whose processor-based emulation functionality fits the embedded-instrumentation category.

Inovys chief scientist Al Crouch addressed the migration of instruments into chips in an ITC presentation titled “The Need for Standard and Efficient Interconnection and Access of Embedded-Everything.” He's been poking around in other people's chips, he said, and he's found a variety of embedded instruments based on technologies from companies including DAFCA, Cisco, ARM, and ASE.

Such instruments are necessary, Crouch said, to help silicon makers keep up with Moore's law and to serve in applications ranging from debug to yield enhancement to system-level troubleshooting. Dense chips and stacked-die multichip packages, he said, require significant debug infrastructure to get them up and running. As for system-level test, he said that a chip might work fine when it's plugged into a $10,000 load board connected to a $2 million ATE system. But when you pack it onto a 5x5-in. board with 10 other chips and connect it to a $35 power supply, it might turn out not to work so well.

Crouch also said that the proliferation of embedded instruments presents its own problems involving the need to communicate with them effectively. He concluded that the IEEE P1687 internal JTAG initiative can provide an effective way for orderly, standardized embedded-instrument communication and control.

Of course, external testers aren't out of the picture. Verigy's announcement that it is purchasing Inovys (See Verigy signs agreement to acquire Inovys) signals that the V93000 ATE system will have a role to play in communicating with chips' internal instruments.