Prof. Dr. Thorsten Jungmann (last updated 2026-10-03)
Robert K. Brayton (1933–2025) was an American electrical engineer and mathematician and professor emeritus in the Department of Electrical Engineering and Computer Sciences at the University of California, Berkeley. He worked in logic synthesis, formal verification and electronic design automation (EDA), with a career spanning over six decades. Born in Des Moines, Iowa, and raised in Ames, he received his bachelor’s degree in electrical engineering from Iowa State University in 1956 and his doctorate in mathematics from the Massachusetts Institute of Technology (MIT) in 1961. He then spent 26 years (1961–1987) at IBM’s T. J. Watson Research Center in Yorktown Heights, New York, where he led the Yorktown Silicon Compiler team. In 1987 he joined the University of California, Berkeley, where he became Cadence Distinguished Professor of Electrical Engineering.
The ESPRESSO logic minimizer (Espresso heuristic logic minimizer) is a computer program for the heuristic minimization of two-level (sum-of-products) logic. ESPRESSO-I was originally developed at IBM by Brayton and co-workers in 1982 and was improved as ESPRESSO-II in 1984; the widely used C version was written at Berkeley by Richard Rudell. Minimization by hand with Karnaugh maps is practical only for up to four variables, and the tabular Quine–McCluskey algorithm is practical only for functions with a limited number of input variables and output functions; Espresso follows a different approach to this problem.
Rather than expanding a logic function into minterms, Espresso manipulates ‘cubes’ that represent the product terms. The result is not guaranteed to be the global minimum, but in practice it comes very close to it, and the solution is always free from redundancy. Compared with the tabular Quine–McCluskey algorithm, Espresso needs far less memory and computation time, and it and its successors are widely used as a minimization step in logic synthesis tools. Brayton received, among other awards, the IEEE Emanuel R. Piore Award (2006), the ACM Paris Kanellakis Theory and Practice Award (2006) and the Phil Kaufman Award (2007), and he was a member of the National Academy of Engineering.
Reference and further reading:
https://en.wikipedia.org/wiki/Robert_K._Brayton
https://en.wikipedia.org/wiki/Espresso_heuristic_logic_minimizer