ARTEMIS: Agile Discovery of Efficient Real-Time Systems-on-Chips in the Heterogeneous Era

Heterogeneous systems-on-chips (SoCs) are pivotal for real-time applications like autonomous driving, as they blend the versatility of CPUs with the efficiency of accelerator IPs. However, evolving application demands necessitate domain-specific SoCs to meet real-time deadlines within strict power and area constraints. While prior research focused on microarchitectural optimizations, overlooking broader system-level considerations can lead to suboptimal design decisions. Thus, there is a need to elevate the abstraction level of design space exploration (DSE) to the SoC level. However, SoC-level DSE is challenging due to the vast design space, encompassing microarchitectural parameters and dynamic task-to-hardware mapping choices based on runtime characteristics and real-time constraints. This paper proposes a systematic and agile methodology, called ARTEMIS, for efficient DSE of real-time, domain-specific SoCs that are constrained by task deadlines, power, and area. The core concept involves integrating a dynamic SoC scheduler to reduce the design space by eliminating the mapping dimension. Enhanced scheduling policies, incorporating techniques like task procrastination and memory-traffic/energy awareness, expedite navigation through the pruned design space. Additionally, DSE heuristics are optimized with real-time deadline and power/areaaware ranking mechanisms. ARTEMIS is evaluated on autonomous vehicle (AV) and augmented/virtual reality (AR/VR) applications, and additionally validated on an FPGA. Compared to the state-of-the-art, DSE using ARTEMIS converges 5.1$12.8 \times$ faster, while yielding SoCs that meet $100 \%$ real-time deadlines with $1.2-3 \times$ better throughput at iso-area or up to $2.4 \times$ lower area for at iso-input-rate. ARTEMIS thus enables DSE of large designs with tractable simulation resources, without compromising on the power-performance-area metrics of the explored SoC design.