Comparative study of test generation methods for simulation accelerators

Hardware-accelerated simulation platforms are quickly becoming a major vehicle for the functional verification of modern systems and processors. Accelerator platforms provide functional verification with valuable simulation cycles. Yet, the high cost and limited bandwidth of accelerator platforms dictate a requirement for continuous utilization improvement. In this work, we perform a comparative analysis of two approaches of test generation for accelerator platforms. An exerciser tool is used as experimental vehicle for the study. An off-platform test generation methodology is implemented and is compared to on-platform test generation typically used in exercisers. We present experimental results from simulation of latest IBM POWER8 processor on Awan accelerator platform, as well as from simulation of an eight-core ARMv8-based design on Veloce emulation platform. Our results indicate that the utilization of accelerator platforms can be improved by up to ×7 ratio when using off-platform test generation. In addition, increase of up to 24% is observed in test coverage. Off-platform mode features significantly bigger image size, but maintains tolerable build and load times.