A solution methodology for exact design space exploration in a three-dimensional design space

This paper describes an exact solution methodology, implemented in Rensselaer´s Voyager design space exploration system, for solving the scheduling problem in a three-dimensional (3-D) design space: the usual two-dimensional (2-D) design space (which trades off area and schedule length), plus a third dimension representing clock length. Unlike design space exploration methodologies which rely on bounds or estimates, this methodology is guaranteed to find the globally optimal solution to a 3-D scheduling problem. Furthermore, this methodology efficiently prunes the search space, eliminating provably inferior design points through the following: 1) a careful selection of candidate clock lengths and 2) tight bounds on the number of functional units or on the schedule length. Both chaining and multicycle operations are supported.