Proof-Carrying Approximate Circuits

Abstract

Approximate circuits (AxCs) tradeoff computational accuracy against improvements in hardware area, delay, or energy consumption. IP core vendors who wish to create such circuits need to convince consumers of the resulting approximation quality. As a solution, we propose proof-carrying AxCs. The vendor creates an approximate IP core together with a certificate that proves the approximation quality. The proof certificate is bundled with the approximate IP core and sent off to the consumer. The consumer can formally verify the approximation quality of the IP core at a fraction of the typical computational cost for formal verification. In this brief, we first make the case for proof-carrying AxCs and then demonstrate the feasibility of the approach by a set of synthesis experiments using an exemplary approximation framework.