Analyzing Real-Time Behavior of Flash Memories

Flash memories are used as the main storage in many portable consumer electronic devices because they are more robust than hard drives. This document gives an overview of existing consumer flash memory technologies which are mostly removable flash memory cards. It discusses to which degree consumer flash devices are suitable for real-time systems and provides a detailed timing analysis of some consumer flash devices. Further, it describes methods to analyze mount times, access performance and timing predictability of flash memories. Important factors which influence access timings of flash memories are pointed out and different flash file systems are evaluated with regard to their suitability for real-time systems. Some remaining problems of existing flash file system implementations concerning real-time use are discussed