Research On The Dispatch Method Of On-Chip Percolation Data For Single-Core Processor

The "Memory Wall" problem has been the bottleneck in processor performance improvement. It is, the great speed gap between processor and memory lead to a mess circumstance that there is a shortage of demand for processor to acquire data from memory. Percolation Delay Tolerance Mechanism is a new way to solve the problem of "Memory Wall". However, there are many shortcomings of the existing percolation technology and these shortcomings can be divided into two aspects:the research contents and the research methods. The shortcomings of research contents include: lack of accurate definition of just-in-time locality and percolation data; the existing percolation technology is major focused on data movement in memory hierarchy that controlled by software technology but ignore the data carrier - the storage space. In fact, the existing memory hierarchy technology, especially the cache technology, is not conducive to the percolation technology. The shortcoming of research methods is that the existing percolation technology mainly proves the effectiveness of percolation delay tolerance mechanism by indirect simulation methods, which leads to the lack of deep understanding the nature of percolation technology.This paper is supported by the open project No.CARCH201307 of State Key Laboratory of Architecture, Institutes of Computing Technology, Chinese Academy. This paper introduces a percolation cache organization principle which is mainly composed of spring-draw cache and spring-push cache. This paper also introduces the idea of data migration by the means of cold percolation and warm percolation.Another main work in this paper is to build a percolation cache simulation platform and a tradition cache simulation platform with Verilog language and ModelSim tool. The tradition cache simulation platform is used to do comparative experiment with the percolation cache simulation platform. These two simulation platforms can be used to study the characteristics of percolation cache and percolation data dispatch method directly instead of indirectly which makes up the shortcomings of research methods of the existing percolation technology. The simulation platforms designed in this paper can flexibly configure the parameters needed by experiments and finally generate the performance reports of cache which includes cache hit rate statistics. The module level verification and system level verification have been carried out in this paper and these two simulation platforms meets the requirements of experiments in present stage.In this paper, three sets of experiments have been designed to study the percolation cache and the percolation data dispatch method. Experiments include two aspect: on one hand, percolation cache and percolation data dispatch method are compared with tradition cache and its data dispatch method; on the other hand, the parameters of percolation cache own and the sum of percolation data items are studied. Experiments show that:percolation cache with the percolation data dispatch method in this paper can be well combined with the percolation technology and has better performance than tradition one.The research work in this paper is of pioneering signification to deeply study the percolation technology in essence.