Optimizing a Flash Manager for NAND Flash Imaging


While the process of preparing and writing images to NOR flash is a straight-forward implementation, creating images for NAND is much more complex, making a uniform programming strategy arduous without the proper flash media management tools. Under the crunch of a product development schedule, it may seem practical to use a hardware simulator to capture an image of a file system, and then write that image to new flash by reading only a part of the flash that is thought to include all of the files. Flash experts would tell you that this is not as simple as it sounds, and is not likely to work reliably.

This paper explores the use of tools within the Datalight FlashFX Pro flash media manager for creating a flash image and initializing fresh NAND flash from this image. We also discuss best practices for high volume production programming of NAND flash… …BBM is Datalight's method of working around the bad blocks that are generally present in NAND flash. Even a brand new flash chip from the manufacturer may have some erase blocks that do not meet specifications for reliable data storage, and further blocks may go bad after extended use. BBM is responsible for allocating replacement blocks and remapping addresses from bad blocks to their corresponding replacement blocks.