It is difficult to use synchronous buses in a system-on-a-chip design due to the increase of wire delay caused by the crosstalk effect and the difficulty of the synchronization caused by the clock-skew problem. The use of an asynchronous bus is an alternative solution for the SoC design method. In this paper, we propose a new high performance asynchronous bus using a return-to-zero data encoding method to get a low latency and a high throughput as well. Simulation results reveal that, by the proposed scheme, the read throughput increases by 17.6%, and the read latency decreases by 12.5% simultaneously.