Standard Cell Like Via-Configurable Logic Blocks for Structured ASIC in an Industrial Design Flow

A structured application-specific integrated circuit (ASIC) has prefabricated yet configurable logic block arrays. We investigate some important via-configurable logic block (VCLB) design issues. We particularly focus on creating a VCLB layout that enables a standard cell like design. We propose the VCLB composability concept which enables us to use multiple VCLB instances to realize a complex logic gate. We devise four new VCLBs and construct several cell libraries based on these VCLBs. We develop a design flow mostly using industrial design tools and propose a method to evaluate VCLB viability. The experimental results show that a medium-grained VCLB that realizes a rich set of logic functions attains the best performance.