McPAT-PVT: Delay and Power Modeling Framework for FinFET Processor Architectures Under PVT Variations

Abstract

As technology has moved into the deep-submicrometer regime, the shrinking feature size has placed a considerable stress on CMOS fabrication due to short-channel effects (SCEs) and excessive leakage. Although many research efforts have been devoted to seeking system-level solutions, underlying transistor-level solutions are still urgently required to overcome these obstacles. FinFETs have emerged as promising substitutes for conventional CMOS due to their superior control of SCEs and process scalability. However, FinFETs still face lithographic and workfunction engineering challenges, in addition to those posed by supply voltage and temperature variations across the integrated circuit (IC). These lead to process, supply voltage, and temperature (PVT) variations in FinFET ICs, which, in turn, lead to large spreads in delay and leakage. In this paper, we present a multicore power, area, and timing (McPAT)-PVT, an integrated framework for the simulation of power, delay, as well as PVT variations of FinFET-based processors. McPAT-PVT uses a FinFET design library, consisting of logic and memory cells, to model circuit-level characteristics as well as their PVT variation trends. It is based on macromodels, derived from very accurate TCAD device simulations that characterize various functional units in a processor under PVT variations, making yield analysis for timing and power for processor components possible. McPAT-PVT can model both shorted-gate (SG) and asymmetric-workfunction shorted-gate (ASG) FinFET-based processors. Combining these macromodels with a FinFET-based CACTI-PVT cache model and an ORION-PVT on-chip network model, McPAT-PVT is able to simulate a delay and power consumption of all processor components under PVT variations. We present extensive simulation results to demonstrate its efficacy, including for an alpha-like processor and multicore simulations based on Princeton Application Repository for Shared-Memory Computers benchmarks. Results show that the ASG FinFET-based processor implementation has $73\times $ lower leakage power and $2.6\times $ lower total power relative to the SG FinFET-based processor implementation for the same performance, with <1% area penalty.