MONTAGE: An FPGA for synchronous and asynchronous circuits

Abstract

Field-programmable gate arrays are frequently used to implement system interfaces and glue logic. However, there has been little attention given to the special problems of these types of circuits in FPGA architectures. In this paper we describe Montage, a Triptych-based FPGA designed for implementing asynchronous logic and interfacing separately-clocked synchronous circuits. Asynchronous circuits have different requirements than synchronous circuits, which make standard FPGAs unusable for asynchronous applications. At the same time, many asynchronous design methodologies allow components with greatly different performance to be substituted for one another, making a design environment which migrates between FPGA, MPGA, and semi-custom implementations very attractive. Similar problems also exist for interfacing separately-clocked synchronous circuits. We discuss these problems, and demonstrate how the Montage FPGA satisfies the demands of these classes of circuits.