This paper presents two high-throughput, low-latency converters that can be used to convert synchronous communication protocol to asynchronous one and vice versa. We have designed these two hardware components to be used in a Globally Asynchronous Locally Synchronous clusterized Multi-Processor System-on-Chip communicating by a fully asynchronous Network-on-Chip. The proposed architecture is rather generic, and allows the system designer to make various trade-offs between latency and robustness, depending on the selected synchronizer. We have physically implemented the two converters with portable ALLIANCE CMOS standard cell library and evaluated the architectures by SPICE simulation for a 90 nm CMOS fabrication process.