ATTEST: Application-Agnostic Testing of a Novel Transistor-Level Programmable Fabric

Abstract

A recently introduced TRAnsistor-level Programmable fabric (TRAP) has demonstrated great promise towards seamless unification of high-density reconfigurable logic with Application-Specific Integrated Circuits (ASICs). However, practical deployment of TRAP relies on the development of a comprehensive mechanism for detecting manufacturing defects. Unfortunately, the state-of-the-art test schemes are developed either for ASICs or for Field-Programmable Gate Arrays (FPGAs) and do not support this new transistor-level architecture. To address this limitation, we present a novel application-agnostic test methodology specifically tailored to the TRAP fabric. We first introduce a multi-phase, cascadable scheme to efficiently test the programmable transistors in TRAP’s Logic Elements (LEs). Then, we define the required test patterns for verifying the correct functionality of the built-in D flip-flop, full-adder, and multiplexer of each LE. Next, we present a systematic approach for testing the interconnect network. Lastly, we discuss the limitations in testing the memory cells used for storing the TRAP programming bits and we propose design modifications for improving test coverage.