Combinatorics and Geometry for the Many-ported, Distributed and Shared Memory Architecture

Manycore SoC architectures based on on-chip shared memory are preferred for flexible and programmable solutions in many application domains. However, the development of many ported memory is becoming increasingly challenging as we approach the end of Moores Law while systems requirements demand larger shared memory and more access ports. Memory can no longer be designed simply to minimize single transaction access time, but must take into account the functionality on the SoC. In this paper we examine a common large memory usage in SoC, where the memory is used as storage for large buffers that are then moved for time scheduled processing. We merge two aspects of many ported memory design, combinatorial analysis of interconnect, and geometric analysis of critical paths, extending both to show that in this case the SoC performance benefits significantly from a hierarchical, distributed and staged architecture with lower-radix switches and fractal randomization of memory bank addressing, along with judicious and geometry aware application of speed up. The results presented show the new architecture supports 20% higher throughput with 20% lower latency and 30% less interconnection area at approximately the same power consumption. We demonstrate the flexibility and scalability of this architecture on silicon from a physical design perspective by taking the design through layout. The architecture enables a much easier implementation flow that works well with physically irregular port access and memory dominant layout, which is a common issue in real designs.