This paper presents one-color two-phase asynchronous communication links for a high-performance asynchronous system. The proposed communication links based on simple one-color encoding is effectively connected to processing cores. Since the communication is controlled by simultaneous handshaking, where a request and an acknowledge signals are overlapped, the number of communication steps is greatly reduced. Moreover, the use of multiple-valued current-mode circuit makes it possible to realize asynchronous communication with just two wires. The asynchronous transmission circuits based on the proposed encoding are implemented and evaluated using HSPICE simulation with 0.13μm CMOS technology. Throughput of the proposed 2-bit transmission attains 0.45Gbps/wire, which is three times faster than that of the conventional two-color two-phase transmission.