New Development Takes the Trial and Error Out of Purging Computer Chips of Bugs

Engineer researchers at the University of Michigan have developed a new and much more efficient system for detecting bugs in a computer chip after they have already been cast in silicon.

Presently, when engineers design chips they first check the validity of the chip design through simulations. They then create a prototype of the chip and cast it in silicon. Next, they have to test the newly made prototype for bugs. If engineers find a bug, they must fix it without disturbing the rest of the sensitive system. It can take several days to fix the prototype. Then the engineers must continue to test each new prototype they create until they finally find one that doesn't have any bugs. This process is nearly becoming impossible because today engineers must create chips that work for nearly all applications including sending e-mail and playing chess. The process of fixing the chip's bugs can take as long as actually designing the chip.

Not only is this system very tedious, it is very difficult for several reasons. First, it is very difficult to track the signals that are hidden in the silicon die or inside the chip. Secondly, silicon chips today can be made so small and are so complex that it is virtually impossible to create a chip that works correctly in every situation.

Researchists at the University of Michigan have created a new system to debug chips that will eliminate this present game of guess and check. Their new system is called FogClear and will be presented by recent doctoral graduate Kai-Hui Chang at the International Conference of Computer-Aided Design in San Jose, California. Chang worked in collaboration with his colleagues Igor Markov and Valerid Bertacco, associate professors of computer science and electrical engineering.

FogClear is a computer-aided system that uses puzzle-solving algorithms to find and diagnose problems so that engineers can adjust the chip's blueprint in the beginning stages of building the chip. FogClear will reduce the work load to designing chips by days.

Another advantage of FogClear is that because it makes the process of finding bugs automated, it can catch subtle errors that would otherwise take months for other simulations to catch. Some bugs are only detected after days or weeks of computation, or after computing under high temperatures.

Also, FogClear will find the simplest way to fix the bugs without impacting the rest of the chip, which generally entails reconnecting the wires. FogClear is predicted to save companies millions of dollars and months of development time.

Nicole Casal Moore, "New computer program automates chip debugging," University of Michigan.