System-on-a-chip (SoC) has emerged to become a cost-effective approach for embedded systems design with rapid advance of semiconductor technology. It allows designers to integrate a number of heterogeneous IP blocks together based on a system interconnect. However, traditional dedicated wiring as the system interconnect has many shortcomings, such as non-scalable global wire delay, failure to achieve global synchronization, and errors due to signal integrity issues. These problems can be mitigated by the network-on-chip (NoC) architecture based on regular on-chip communication networks. In this paper, we present three efficient switch designs for NoC systems based on circuiting switching. Such switch designs with efficient buffer management can provide the on-chip network with guaranteed throughput and transmission latencies.