The Research Of CRAM Storage Architecture And Optimization Algorithm

With the evolution of semiconductor industry, nonvolatile memory has been going through our daily life. Chalcogenide Random Access Memory CRAM belongs to a new generation of nonvolatile memory. It has great advantages in storage density, access time, power dissipation, and reliability, so that it is expected to be the replacement of the current prevalent Flash memory(Flash).Developing CRAM storage system, and applying it to the traditional computer system, will play a great role in the evolution of semiconductor industry.This paper designed the framework of CRAM storage system, which is based on the traditional computer storage hierarchy. According to the physical characteristic of CRAM basic cell, respectively from the cache-main storage and the main storage-auxiliary storage. These two storage levels of CRAM storage architecture was designed and researched.The driving circuit for reading or writing Phase Change Memory has very much difference with past memory, but its function module is similar with flash. This paper carefully studied the difference and similarity of flash and CRAM respectively on the memory cell and the memory array,and then designed the CRAM and writing/driving circuit and the memory chips, and took on the simulation analysis, with the help of Hspice software, got the CRAM pulse waveform for reading/writing the cells.After phase change memory has been used for computer system, due to its unique features on reading and writing, the system scheduling optimization need to be researched. The mathematical model of task scheduling was presented in this paper, through selecting the shortest branch and repeatedly calculating, the system task scheduling scheme has been analyzed. Different ways of task scheduling were calculated respectively with the help of Code-blocks software. At last, data distribution scheme was researched, all kinds of data distribution were worked out with Code-blocks software. Calculation results show that the use of task scheduling optimization methods and data distribution optimization method are successful on the reduce of writing on the CRAM, thus improve the CRAM software running speed in the storage system, and prolong the life of CRAM cell.