Asynchronous on-chip network

Abstract

An on-chip network (NoC) is a critical component of a GPU, CPU, network switch, or accelerator. The network nodes may be arranged in a two-dimensional array with each network node coupled to neighboring network nodes vertically and horizontally, with or without diagonal connections. Conventional routers within network nodes are synchronous, taking from 1-10 clock cycles to determine an output port, arbitrate between virtual and physical channels, and account for credits. In contrast, in an embodiment, transmission of a packet between network nodes often occurs in less than one clock cycle because the handshake protocol and the circuitry are not synchronized using a clock signal. When implemented using asynchronous logic, the routing delay and power are reduced. The channel latency is the minimum time needed to drive the physical traces. Such an asynchronous NoC may reduce latency by a factor of two or more compared with a synchronous NoC.