The Impact of Interconnect Architecture on Via-Programmed Structured ASICs (VPSAs)

Usman Ahmed,  Guy Lemieux,  Steve Wilton
University of British Columbia


Abstract

In this paper, we evaluate the performance of an FPGA-like interconnect fabric for structured ASICs which is based upon fixed metal and programmable vias. We call this type of device a via-programmed structured ASIC or VPSA. We look at two different types of VPSA routing fabrics: one uses jumper wiring and the other uses crossover wiring. The performance of these fabrics is compared against an ASIC-like interconnect fabric, otherwise known as a metal-programmed structured ASIC or MPSA, which can be configured by customizing metal and via layers. We study the impact of these routing fabrics on cost, area, power and delay metrics. The results show there is a significant variation between the performance of different via-programmable fabrics, suggesting that the routing architecture plays a very important role in their overall performance and it should be thoroughly researched.