Dataflow-Specific Algorithms for Resource-Constrained Scheduling and Memory Design

Abhishek Bhattacharjee, Quanquan C. Liu, Rajit Manohar, Raghavendra Pothukuchi, and Muhammed Ugur

We introduce the Weighted Red-Blue Pebble Game, an extension of the classic red-blue pebble game with weighted operation costs. This weighted formulation enables constant-factor analysis of highly resource-constrained systems with bounded fast memory, unlimited slow memory, and strict energy and power constraints.

We apply our model to computational kernels in ultra-low-power brain-computer interfaces (BCIs) implanted near the brain. We express these kernels as computational directed acyclic graphs (CDAGs), enabling modular composition of operation schedules with data movement. We derive theoretically optimal schedules for a broad class of tree-structured CDAGs and apply them to on-chip memory design with circuit-level validations for power and area.

Our algorithms result in an average 63% memory area reduction and 43% static power reduction for BCI workloads—critical improvements for ensuring safe, thermally constrained operation in implantable devices. Beyond BCIs, our results underscore the broader utility of weighted pebble games in optimizing memory and I/O across resource-constrained computing environments.

 
  
Yale