On the design and performance of conventional pipelined architectures

Abstract

Pipelining is a widely used technique for implementing architectures that have inherent temporal parallelism when there is an operational requirement for high throughput. Many variations on the basic theme have been proposed, with varying degrees of success. The aim of this paper is to present a critical review of conventional pipelined architectures and put some well-known problems in sharp relief. It is argued that conventional pipelined architectures have underlying limitations that can only be dealt with by adopting a different view of pipelining. These limitations are explained in terms of discontinuities in the flow of instructions and data, an d representative machines are examined in support of this argument. In a companion paper [Topham, Omondi and Ibbett, 1988] we examine an alternative approach to the design of pipelined architectures and introduce an alternative theory of pipelining, which we call Context Flow.

Context flow: An alternative to conventional pipelined architectures

“…This report (including Topham, Omondi, and Ibbett [1988]) has surveyed a number of proposals for radically different styles of pipeline. Most notable among these are the HEP, and CPC, and the CCMP.…”

“…However, there are discontinuities with much finer levels of granularity than this [Topham, Omondi, and Ibbett 1988]. For example, when an instruction within a pipeline needs an operand from main store, a pipeline discontinuity normally occurs.…”