Integrating Tree PLRU Replacement Policies and Bypass Techniques in a 4-Way Set Associative Cache Controllers

Cache memory plays a crucial role in bridging the performance gap between high-speed processors and slower main memory. This paper presents a 4-way set-associative cache controller, implemented in Verilog using Xilinx Vivado 2023.2, integrating the Tree-based Pseudo Least Recently Used (PLRU) replacement policy with an advanced bypass mechanism to optimize cache utilization and reduce cache pollution. The Tree PLRU algorithm improves replacement efficiency while minimizing hardware complexity, and the bypass mechanism selectively prevents non-reusable data from occupying cache space, enhancing hit rates. Simulation results demonstrate a 96% cache hit rate, surpassing conventional methods like LRU (85%), FIFO (75%), and LFU (78%) while achieving lower power consumption (320mW) compared to LRU (400mW). The comparative analysis confirms the superiority of this approach in reducing cache misses, improving system responsiveness, and lowering latency. Future work will focus on FPGA implementation to evaluate real-world power consumption, scalability, and adaptive techniques for dynamic workload optimization, ensuring a balance between performance and resource efficiency.