The functionality of DRAMs, especially the state transitions are described in JEDEC standards. These standards contain a finite state machine, which intends to provide an overview of the possible state transitions and the commands to control them. However, today's DRAMs are highly concurrent devices as they provide bank parallelism. The state diagram used in JEDEC standards does not model this concurrency and furthermore it is misleading in several aspects. In this paper, for the first time we present an easily comprehensive model of the DRAM states and transitions, using a Petri Net, which covers also the DRAM concurrency.

Fast Validation of DRAM Protocols with Timed Petri Nets M.Jung, K.Kraft, T. Soliman, C. Sudarshan, C. Weis and N.Wehn ACM/IEEE International Symposium on Memory Systems (MEMSYS 2019), October, 2019, Washington, DC, USA

A New State Model for DRAMs Using Petri Nets (Link) M. Jung, K. Kraft, N. Wehn. IEEE International Conference on Embedded Computer Systems Architectures Modeling and Simulation (SAMOS), July, 2017, Samos Island, Greece.

In order to run the executable models click here, or open the index.html file in the web folder after cloning the repository. For security reasons, access to files on the file system is disabled by default from the browser. The following it is described how to adapt Chrome and Firefox to run index.html locally.

Chrome

Close all running chrome instances. Edit the way how you start chrome (on shortcut -> Properties -> Target). Change the Target path to: "C:\yourpath\chrome.exe" --allow-file-access-from-files

Firefox

Open Firefox. Navigate to about:config . Search for (CTRL+F) security.fileuri.strict_origin_policy and toggle the parameter to true.

In order to explore different architectures the PNEditor (version >=0.71) can be used. The files for the PNEditor are stored in the pflow folder.