A Switch Wrapper Design for SNA On-Chip-Network

In this paper we present a design of a switch wrapper as a component of SNA (SoC network architecture), which is an efficient on-chip-network compared to a shared bus architecture in a SoC. The SNA uses crossbar routers to provide the increasing demand on communication bandwidth within a single chip. A switch wrapper for SNA is located between a crossbar router and IPs connecting them together. It carries out a mode of routing to assist crossbar routers and executes protocol conversions to provide compatibility in IP reuse. A switch wrapper consists of a direct router, two AHB-SNP converters, two interface sockets and a controller module. We implement it in VHDL. Using ModelSim simulation, we confirm the functionality of the switch wrapper. We synthesize it using a Xilinx Virtex2 device to determine resource requirements: The switch wrapper seems to occupy appropriate spaces, about 900 gates, considering that a single SNA crossbar router costs about 20,000 gates.