Hybrid simulation for extensible processor cores

Due to their good flexibility-performance trade-off, Application Specific Instruction-set Processors (ASIPs) have been identified as a valuable component in modern embedded systems, especially the extensible ones, achieving good cost-efficiency trade-offs. Since the generation of the described hardware is usually automated to a high extent, in order to deliver an ASIP-based design in due time, developers are limited by the performance of the underlying simulation techniques for software development. On the other hand, the Hybrid Processor simulation technology (HySim), which enables dynamic run-time switching between native and instruction-accurate simulation, has reported high speed-up values for some fixed architectures. This paper presents enhanced HySim technology for extensible cores, based on a layered simulation infrastructure. This technology has shown a speed-up on a per-function basis of two orders of magnitude for a realistic MIMO OFDM benchmark on a multi-core platform with customized Xtensa cores by Tensilica.