RT-PLRU: A New Paging Scheme for Real--Time Execution of Program Codes on NAND Flash Memory for Portable Media Players

NAND flash memory has been widely used as a nonvolatile storage for storing data. However, it is challenging to execute program codes on NAND flash memory, since NAND flash memory only supports page-based reads, not byte-level random reads. This paper proposes an automated process to find the optimal paging strategy called RT-PLRU (Real-Time constrained combination of Pinning and LRU) that allows program codes stored in NAND flash memory to be executed satisfying real-time requirements with minimal usage of RAM. Moreover, the proposed process optimally configure the RT-PLRU in a developer-transparent way without giving any burden to the program developer. The developed technique is specifically applied to a media player program targeting a portable media player (PMP). To the best of our knowledge, this is the first effort to use NAND flash memory as a code storage for storing and executing real-time programs with minimal usage of RAM.