MS thesis defense

A Fast Fullchip Transient Response Estimation Technique

Sushmita K. Rao

11:00am Monday, 25 July 2011, ITE 346

Circuit Simulation has long been a dependable technique for design engineers for functional testing before a circuit is taken to silicon. But as we move into very deep sub-micron technologies, chips are becoming more complex and denser. The dense power grid adds to long simulation run time rendering fullchip simulations difficult and computationally expensive for larger designs. Some large designs may not be simulatable owing to system requirements. Even fast simulators like Cadence UltraSim fail to provide SPICE level accuracy. Dynamic solutions provide greater accuracy than statistical techniques but long simulation run time becomes the biggest tradeoff. Accurate measurement of dynamic currents is required for applications like power estimation, supply noise predictions and in verifying the power grid designs and testing. The research reported in this thesis is focussed on providing a current based method to estimate a fullchip's transient response without carrying out a fullchip simulation. Instead, a part of the chip is simulated and the power port currents thus measured are used to estimate the fullchip currents using the principle of superposition. This technique eliminates fullchip simulations that are complex and time consuming but the accuracy is maintained as the fullchip estimation is carried out on simulated data. A simple scaling method is also proposed to compensate for resistive variations in the test circuits. Experimental results reported demonstrate the effectiveness of the method.

Committee members:

• Dr. Chintan Patel (Chair)
• Dr. Ryan Robucci
• Dr. Tinoosh Mohsenin

Dr. Penny Rheingans, professor of computer science and electrical engineering, co-directs UMBC's VAnGOGH lab, where she uses her knowledge in data visualization to solve problems in a variety of application areas. “I think it’s a really cool area because it allows me to synthesize things from a number of areas,” says Rheingans of the field, which allows her to combine techniques from computer graphics, art and illustration, and knowledge of human perceptual and cognitive systems.

To read more about Dr. Rheingans' research pursuits, see her full research profile.

Dr. Tinoosh Mohsenin, professor of computer science and electrical engeineering, runs UMBC's Engergy Efficient High Performance Computing Lab, where she works to develop highly accurate, low-power communications and healthcare devices. Currently, Dr. Mohsenin is pursuing three distinct projects in conjunction with her lab that fall within the realm of digital signal processing (DSP) and VLSI implementation: 1) many-core architectures for DSP and secured trusted platforms, 2) low-power processors for portable healthcare devices, and 3)efficient error correction techniques for communication devices.

To read more about Dr. Mohsenin's research pursuits, see her full research profile.

Dr. Fow-Sen Choa, professor of computer science and electrical engineering, uses a Chemical Vapor Desposition System to grow semiconductors that are used for chemical detection and breath analysis using photo-acoustic (PA) effects. In addition, he has been working with undergraduate students at UMBC on projects dealing with flying robots, Fourier analysis of music instrument, x-ray scan of superlattice crystal growths, and brainwave measurement and analysis.

To read more about Dr. Choa's research pursuits, see his full research profile.

UMBC was recognized as a “Great College to Work For” in a survey done by the Chronicle of Higher Education. The 2011 survey was based on responses from nearly 44,000 people at 310 US institutions. UMBC was as one of ten large four-year colleges (> 10K students) selected for the honor roll based on its scores on nearly 100 questions across twelve key categories.

UMBC was recognized as a “Great College to Work For” in a survey done by the Chronicle of Higher Education. The 2011 survey was based on responses from nearly 44,000 people at 310 US institutions. UMBC was as one of ten large four-year colleges (> 10K students) selected for the honor roll based on its scores on nearly 100 questions across twelve key categories.

This week’s story on This American Life, When Patents Attack, is a good introduction to how the patent system is being used and abused, especially in the software industry. I listened to it today and got new insights into a complex problem. It will be aired on WYPR (88.1) at 4:00pm Sunday and available for for online listening or downloading after 7:00pm on Sunday. The text of the show is available now on NPR’s Planet Money blog. Here’s how it starts…

Nathan Myhrvold is a genius and a polymath. He made hundreds of millions of dollars as Microsoft’s chief technology officer, he’s discovered dinosaur fossils, and he recently co-authored a six-volume cookbook that “reveals science-inspired techniques for preparing food.”

Myhrvold has more than 100 patents to his name, and he’s cast himself as a man determined to give his fellow inventors their due. In 2000, he founded a company called Intellectual Ventures, which he calls “a company that invests in invention.”

But Myhrvold’s company has a different image among many Silicon Valley insiders.

The influential blog Techdirt regularly refers to Intellectual Ventures as a patent troll. IPWatchdog, an intellectual property site, called IV “patent troll public enemy #1.” These blogs write about how Intellectual Ventures has amassed one of the largest patent portfolios in existence and is going around to technology companies demanding money to license these patents.

Patents are a big deal in the software industry right now. Lawsuits are proliferating. Big technology companies are spending billions of dollars to buy up huge patent portfolios in order to defend themselves. Computer programmers say patents are hindering innovation.

But people at companies that have been approached by Intellectual Ventures don’t want to talk publicly.

“There is a lot of fear about Intellectual Ventures,” says Chris Sacca, a venture capitalist who was an early investor in Twitter, among other companies. “You don’t want to make yourself a target.”

Sacca wouldn’t say if Intellectual Ventures had been in contact with any of the companies he’s invested in.

“I tried to put you in touch with other people in this community to talk to you about this and they almost uniformly said they couldn’t talk to you,” Sacca told us. “They were afraid to.” IV has the power to “literally obliterate startups,” Sacca says.

It’s well worth reading or listening to to understand how the current patent system in the US is effecting not only business, but also the disciplines that produce new ideas and inventions in science, technology, engineering and mathematics.