Hierarchical Module Expansion in a VHDL Behavioural Synthesis System

Description/Abstract

This paper describes a technique developed in the MOODS (Multiple Objective Optimisation in Data and control path Synthesis) behavioural VHDL synthesis system whereby functional data-path modules may be dynamically expanded in-situ during the optimisation process, replacing the original �black box� implementation by its constituent sub-components within the top-level control and data path structure. This enables inter-module optimisation to occur at the sub-module level resulting in substantial area reductions, particularly when targeting restricted device architectures with a limited range of primitive cells, such as FPGAs.