High-level modeling and simulation of single-chip programmable heterogeneous multiprocessors

Abstract

Heterogeneous multiprocessing is the future of chip design with the potential for tens to hundreds of programmable elements on single chips within the next several years. These chips will have heterogeneous, programmable hardware elements that lead to different execution times for the same software executing on different resources as well as a mix of desktop-style and embedded-style software. They will also have a layer of programming across multiple programmable elements forming the basis of a new kind of programmable system which we refer to as a Programmable Heterogeneous Multiprocessor (PHM). Current modeling approaches use instruction set simulation for performance modeling, but this will become far too prohibitive in terms of simulation time for these larger designs. The fundamental question is what the next higher level of design will be. The high-level modeling, simulation and design required for these programmable systems poses unique challenges, representing a break from traditional hardware design. Programmable systems, including layered concurrent software executing via schedulers on concurrent hardware, are not characterizable with traditional component-based hierarchical composition approaches, including discrete event simulation. We describe the foundations of our layered approach to modeling and performance simulation of PHMs, showing an example design space of a network processor explored using our simulation approach.