US Patent 7903474 Redundant purge for flash storage device

A flash storage device includes flash storage units that are purged in response to a condition or command. A flash controller interface receives a command for purging the flash storage device and provides a purge command to flash controllers in the flash storage device. Alternatively, the flash storage device detects a condition in response to which the flash controller interface provides a purge command to the flash controllers. Each flash controller independently erases a flash storage unit in response to receiving the purge command, by writing a pattern of data to the flash storage unit, such that the flash storage units are purged substantially in parallel with each other.