Design and evaluation of a four-port data cache for high instruction level parallelism reconfigurable processors

This paper explores high-bandwidth data cache designs for a coarse-grained reconfigurable architecture processor family capable of achieving a high degree of instruction level parallelism. To meet stringent power, area and time-to-market constraints, we take an architectural approach rather than circuit-level multi-porting approaches. We closely examine two design choices: single-level banked cache (SLC) and two-level cache (TLC). A detailed simulation study using a set of microbenchmarks and industry-strength benchmarks finds that both SLC and TLC offer a reasonably competitive performance at a small implementation cost compared with a hypothetical cache with perfect ports and a multi-bank scratchpad memory.