Increasing complexity of a system-on-chip design demands efficient on-chip interconnection architecture such as on-chip network to overcome limitations of bus architecture. In this brief, we propose a packet-switched on-chip interconnection network architecture, through which multiple processing units of different clock frequencies can communicate with each other without global synchronization. The architecture is analyzed in terms of area and energy consumption, and implementation issues on building blocks are addressed for cost-effective design. A test chip is implemented using 0.38-mu m CMOS technology, and measured its operation at 800 MHz to demonstrate its feasibility.