GALS systems prototyping using multiclock FPGAs and asynchronous network-on-chips

This paper presents an innovating methodology for network-centric globally-asynchronous locally-synchronous (GALS) system prototyping. High-performance multiclock FPGAs are exploited for easy and fast prototyping of GALS systems based of an asynchronous network-on-chip (ANoC) interfacing synchronous standard IP cores. Modularity property of asynchronous circuits is fully exploited to design regular distributed interconnect topologies by the means of basic topology-free building blocks, with a focus and special design effort to solve arbitration and synchronization problems. A case-study is implemented on an up-to-date FPGA which includes two independently clocked processors, memory banks, serial and parallel communication links and an asynchronous DES (data encryption standard) module connected through an asynchronous 5×5 crossbar. The clock-less modules are implemented using a quasidelay insensitive logic on the FPGA by the means of a dedicated library. Performance figures are reported on the FPGA platform, especially for communication costs, speed and latency of the ANoC.