An Efficient C++ Framework for Cycle-Based Simulation

System design usually begins with a high-level software simulation which is later refined to a detailed hardware description. A simulation framework can facilitate this process by automating certain hardware abstractions, providing important debugging support, and allowing the transition from a high-level simulation to a low-level hardware description to occur within a single code base. This paper discusses our experience with Sim, a C++ framework developed as an internal tool for cycle-based simulations. We describe the features of Sim which were found to be most helpful to the design process, and we compare Sim to a publicly available simulation framework. The Sim framework is efficient; typical lowlevel hardware simulations run with a slowdown of less than 2x compared to straight C++ implementations.