Micro Digital has enhanced its smxFLogT flash logger to permit multiple logs to be recorded and read back, thus making it more like a conventional file system. FAT file systems typically aren't good for logging data to flash memory because flash, unlike magnetic media, can't be overwritten without first erasing it. The erase operation is slow and must be done in large blocks (32 kbytes bytes or more). Logging a small amount of data can result in moving and rewriting three blocks for data, FAT, and directory. This is inefficient, slow, and could prematurely wear out the flash device.
smxFLog permits efficient, fast, reliable logging of data to flash memory. It supports all types of flash memory—NAND, NOR, serial NOR, and arrays—and works with flash memory of any size. It's suited to the basic nature of flash memory, as it doesn't attempt to do anything fancy, just log the data. Furthermore, it's power-fail safe, making it suitable for applications where high reliability is a must, such as down-hole instruments, engine monitoring, or any application that requires reliable, unattended logging of data to flash memory.
While smxFLog also has a small memory footprint, 2 to 4 kbytes of code and 32 to 288 bytes of RAM, it provides wear leveling, bad-block handling, read back and verify, block erase, and optional error-code correction (ECC). Write speed is over 69% of raw flash speed and read speed is over 86% of raw flash speed. Minimum record size can be adjusted to the characteristics of the flash device. Each log can either stop at the end of its partition or loop back and overwrite the oldest information.
smxFLog is available now. The price for a single-product, royalty-free license is $2500, including one low-level flash driver. For further information, go to www.smxrtos.com/fs.