Logical pipeline for data communications system

Abstract

A new type of pipeline, generally referred to as a logical pipeline is disclosed. A logical pipeline generaly includes a set of hardware based pipeline stages that exchange data through a common pipeline memory, instead of only through intermediate fixed physical buffers. Thus, operational data is retrieved and stored by each stage using a single memory, and this permits flexible and programmable forms of pipelines that can be adapted as needed in response to a desired computation task. A common pipeline clock initiates processing of the data. Another variation is disclosed in the form of a logical 'hybrid' pipeline, consisting of both software and hardware based pipeline stages, that are used to perform a set of computations in an interleaved fashion. In this manner, a data item can be handled first by a hardware pipeline stage, followed immediately by a software pipeline stage, etc. Furthermore, in a communications system, this arrangement permits processing for a number of ports to be distributed so that at any pipeline clock period, both hardware and software stages can be operating on different ports, or different communication tasks (i.e., transmit and receive).