Write-once memory array controller, system, and method

Abstract

A write-once memory device includes a memory array controller and an electronically resetable flag. The memory array controller prevents writing and erasing from a write-once memory array unless the flag is in a selected state. The memory device is used with a data storage system that automatically determines whether a memory device installed in the data storage system is a write-once memory, and then automatically sends a recognition signal to the memory device once it has been determined to be a write-once memory. The memory device (1) automatically sets the flag in response to the recognition signal, (2) automatically refuses to implement write and erase commands prior to receipt of the recognition signal and setting of the flag, and (3) implements write and erase commands subsequent to receipt of the recognition signal and setting of the flag. The memory device implements nondestructive commands such as read and status commands regardless of the state of the flag.