Multi-Functional Interfaces for Accelerators

Heterogeneous System-on-Chip (SoC) architectures combine general-purpose processors with many accelerators, which are application-specific computing engines. By having their hardware optimized to perform specific tasks, accelerators deliver massive speedups and energy savings compared to corresponding software executions on a processor. Heterogeneity and hardware specialization complicate accelerator design and integration, reducing regularity and reusability across platforms. The many system-level architectural aspects to consider make it hard to explore the design space and arrive to optimal solutions. Furthermore, integrating accelerators affects the programmability of the applications and the security of the entire SoC. In this dissertation, I present design methodologies and architectural contributions that use multi-functional interfaces to simplify many of the tasks that designers perform when designing and integrating accelerators in heterogeneous SoCs. The accelerator interfaces exploit latency-insensitive design to effectively explore the design space when multiple accelerators are integrated and to speed up the verification of accelerators. This improves their reusability across SoC platforms, while ensuring correctness when the accelerators are integrated with the various components of the SoC. In addition, the accelerator interfaces improve the integration with software by making it transparent and by establishing a strong layer of protection between accelerators and applications.The interfaces aim at securing the accelerators and the applications without requiring modifications to the accelerator implementations and without degrading their performance and energy efficiency