The Modeling Of Phase Change Memory And The Design And Implement Of The Simulator

As the production process of DRAM is gradually reaching the limitation,resulting in the poor scalability of DRAM.DRAM has been unable to meet the requirements of current market for high-performance,high-capality memory.Phase change memory(PCM)is a new kind of memory,which is widely concerned for the advantages of nonvolatility,high integration,low static power consumption,byte-addressing,etc.PCM is considered to be a powerful competitor to substitute DRAM.However,PCM also has some shortcomings such as limited write endurance,long write latency and high write power,which restrict the wide adoption of PCM production as main memory.For the research of PCM,it will cost much time and money to simulate the real PCM device.So it is necessary to provide a simulator that can simulate the behavior of PCM accurately.Simulating PCM with Software will be much helpful.In this paper we designed a simulator for accurately simulating of the read and write behavior of PCM in every circle.The main work is as fellows:Firstly,we create a model of PCM based on its characteristic.Then,we present a novel simulator for PCM based on the former model and the differences between PCM and DRAM.The PCM simulator,PCMSim,is realized by rewriting the code of the simulator DRAMSim2.We rewrite the code in two aspects:the rewriting for fitting the real behavior of PCM and the rewriting for expansion.The former work need to rewrite the device configuration information,refresh mechanism,write-back process.The latter work is for the purpose of extending the lifetime of PCM for some situations.In the latter work we add a configurable lifetime-model and two kinds of wear-leveling algorithms.The users can configure the expanded parts in the system config file for their own requirements.The PCMSim is drived by the clock cycles,it can reflect the access delay and energy consumption of PCM equipment.Finally,experimental platform is built to test the above-mentioned simulator.We obtained the delay and the lifetime of PCM in different scenes.We compared the delay without configuring lifetime-model and wear-leveling to verify the correctness of the simulator.After a general comparison of the former evaluation index,we verified the effectiveness of the simulator.