Design Space Exploration of L1 Data Caches for FPGA-Based Multiprocessor Systems

Combining multi-processing with the high level of configurability possible with FPGA-based soft-processors, this paper presents a multiprocessing framework based on the MicroBlaze soft-processor that provides multicore support and fully coherent, independently configurable Level 1 Caches with Linux multicore support. This architecture allows for fine-grain configurability of the system, allowing for FPGA resources to be better optimized for a specific embedded application. We use our framework to explore the L1 Data Cache configuration, developing a metric for efficiency based on resource usage and static application runtime. We find that a Pseudo-Random replacement policy is consistently the more efficient choice for FPGA systems.