Legacy off-chip interconnects overview

Connecting devices together using off-chip buses and interfaces is necessary to construct an electronics system made up of many integrated circuits (ICs). The need to use these buses is to satisfy the requirements of these ICs to exchange data as they collaborate to implement a more complex function in comparison to what they can achieve on their own. The electronics industry has seen the emergence of many standards and protocols to address this need, and the choice of using a specific protocol depends on many factors, such as the physical IO standards, the speed that these buses can run at, the implementation cost, the versatility of the protocol in the industry, the throughput that they can provide, and so on. We distinguish between two main categories of buses in legacy and modern systems: the protocols suited to carry control data and signaling between devices, and the buses that carry high-throughput payload data at a relatively high speed...