Research goals: Modern compute platforms for machine learning are moving from single-core architecture towards heterogeneous multi-core area, which consists of richer datapath blocks, more complex memory hierarchies and more flexible interconnect. One example of such heterogeneous systems for AI application is KU Leuven’s Diana chip, which combines a RISC-V processor, a pure digital accelerator and an analog In-Memory Computing core. Though the hardware becomes more efficient, the increasing degree of design freedom and the complex interaction within multi-core systems make the run-time performance highly stochastic and no longer deterministic. To rapidly explore the system choices under different variation impacts, an uncertainty-aware design space exploration (DSE) framework is crucial to estimate the trade-off on the hardware level.
Gap in the SotA: State-of-the-art DSE frameworks are all based on deterministic cost models and overlook the uncertainties happening within a system, such as PVT variations, memory run-time conflict and diverse workload-dependent dataflow. These unrealistic assumptions create discrepancy between the model estimation and real chip performance, which prevents researchers from accurately understanding uncertainty impact on the hardware.
Result: This project aims to develop a probabilistic DSE framework covering the uncertain impact for multi-core AI accelerators, starting from our ZigZag (and Stream) DSE framework. The ultimate framework will enable analytically estimating the hardware cost variation under different types of uncertainties.