Electrical & Computer Engineering     |     Carnegie Mellon

Tuesday, May 1, 12:15-1:15 p.m. HH-1112


Natasa Miskov-Zivanov
Carnegie Mellon University

MARS-S: Modeling and Reduction of Soft Errors in Sequential Circuits

Once regarded as a concern only for space applications, transient faults caused by radiation are becoming a major barrier to robust system design manufactured at advanced technology nodes like 90nm, 65nm or smaller. Traditionally, memory elements have been much more sensitive to soft errors than combinational logic circuits. However, with technology scaling soft error rate (SER) in combinational logic is increasing with every technology node. Moreover, once a single-event transient induced by radiation can propagate freely through combinational circuit, sequential circuits will become very sensitive to such events. This is due to the fact that, once latched, soft errors can propagate through the sequential circuit in subsequent clock cycles and thus affect the outputs of the circuit more than once. Therefore, the protection from radiation induced transient faults has become as important as other product characteristics such as performance or power consumption.

In this talk, I will present our approach to evaluating the susceptibility of sequential circuits to soft errors. The SER evaluation is demonstrated by the set of experimental results, which show that, for most of the benchmarks used, the SER decreases well below a given threshold within ten clock cycles after the hit. The framework we created can be used for selective gate sizing targeting radiation hardening, which is done only for gates with error impact exceeding a certain threshold. Using such a technique SER can be reduced up to 80% for various threshold values, when applied to a subset of ISCASÕ89 benchmarks.


Natasa Miskov-Zivanov is a Ph.D. candidate in the Electrical and Computer Engineering Department at Carnegie Mellon University, under the guidance of Professor Diana Marculescu. She received her M.S. degree in Electrical and Computer Engineering from Carnegie Mellon University in 2005 and a B.S. degree in Electrical Engineering and Computer Science from University of Novi Sad, Serbia, in 2003. Her current research focuses on reliability analysis and fault-tolerance in nanoscale designs.