Part number : SM3257EN
Functions : High Speed USB2.0 Flash Memory Controller
Package information : LQFP/TQFP 48pin
Manufacturer : Silicon Motion
The SM3257EN is a feature-enhanced USB2.0 Flash Disk controller with high compatibility and best performance designed to support MLC and TLC NAND flash. The controller also supports high speed ONFI 2.x and Toggle mode NAND. Compliant with USB version2.0 specification and USB Mass Storage Class version 1.0 specification, the SM3257EN provides write protect, PC boot-up from USB2.0 Flash Disk, password protection, secured partitioning functions, etc.
Reference site : http://flash-extractor.com/forum/viewtopic.php?t=5616
SM3257EN Datasheet PDF