An exact methodology for scheduling in a 3D 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 3-dimensional (3D) design space: the usual 2D 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 the 3D scheduling problem. Furthermore, this methodology efficiently prunes the search space, eliminating provably inferior design points through: a careful selection of candidate clock lengths; and tight bounds on the number of functional units of each type or on the schedule length.