Design and Characterization of Null Convention Self-Timed Multipliers

We present various 4-bit × 4-bit unsigned multipliers designed using the delay-insensitive convention logic (NCL) paradigm. They represent bit-serial, iterative, and fully parallel multiplication architectures. NCL is a self-timed logic paradigm in which control is inherent in each datum. NCL follows the so-called weak conditions of Seitzʹs delay-insensitive signaling scheme. Like other delay-insensitive logic methods, the NCL paradigm assumes that forks in wires are isochronic. NCL uses symbolic completeness of expression to achieve delay-insensitive behavior. Simulation results show a large variance in circuit performance in terms of power, area, and speed. This study serve as a good reference for designers who wish to accomplish high-performance, low-power implementations of clockless digital VLSI circuits.