Fast transaction-level dynamic power consumption modelling in priority preemptive wormhole switching networks on chip

Abstract

This paper specifies an architecture for power consumption modelling integrated within cycle-approximate transaction level modelling for network-on-chip (NoC) simulation. NoC simulations during design validation have traditionally been limited to very short durations, due to the necessity to perform cycle-accurate simulation to represent fully the low level system simulated. Due to the high proportion of overall system power that may be consumed by a busy NoC, high-fidelity NoC power modelling is especially important to accurately assess the effectiveness of link coding and other strategies to reduce NoC power consumption. The paper describes the extension of a cycle-approximate TLM methodology to encompass power modelling in NoCs, considering its operation with real application traffic. The proposed scheme avoids modelling of flit-by-flit progress during non-preemptive periods of packet transmission. The simulation performance and accuracy are contrasted with theoretical models and a flit-by-flit scheme (in which each flow control digit passing along a bus wire is simulated). The power consumption reduction delivered by encoding schemes such as bus-invert coding are considered and compared with analytical models to verify the correct performance of the simulation models.