RapidIO: The Next Generation Communication Fabric For Embedded Application

12.1. INTRODUCTION

The data streaming logical layer is different from the other logical layers in several ways. Data 'streams' are defined as persistent relationships between a source or ingress device, and a destination or egress device. A data stream contains multiple unidirectional transactions separated by discrete intervals of time. The gaps in time between transactions allow many streams to exist simultaneously in a system, and enable the traffic to share a single fabric. A system's ability to manage the quality of service (QoS) offered to the individual streams determines the utilization of the fabric's resources as well as the faithful preservation of each stream's transaction relationships. All of these factors are components of the data streaming logical layer transaction protocol.

The purpose of the RapidIO data streaming logical layer is to provide a standard approach for encapsulation and transport of data streams across a RapidIO fabric. Figure 12.1 shows how RapidIO might be able to interface to a range of data and control elements that might be typically present in a communications system.

The RapidIO Trade Association, to highlight the capabilities of the data streaming logical layer and other newer features of the RapidIO interconnect technology, has coined the term RapidFabric™. RapidFabric is meant to describe the use of RapidIO in dataplane connectivity applications. For a product to claim RapidFabric support, it should at least support the following RapidIO ...