Nonvolatile memory using flexible erasing methods and method and system for using same

• US 6,587,382 B1
• Filed: 06/19/2002
• Issued: 07/01/2003
• Est. Priority Date: 03/31/1997
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Lexar Media Incorporated (Micron Technology, Inc.)
• Inventors: Keshtbod, Parviz, Nemazie, Siamack, Estakhri, Petro, Assar, Mahmud
• Primary Examiner(s): Dinh, Son T.
• Application Number:
  US10/175,928
• Time in Patent Office: 377 Days
• Field of Search: 365/185.29, 365/185.11, 365/218, 365/230.03
• US Class Current: 365/185.29
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G11C 16/08 Address circuits; Decoders; Word-line control circuits
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

An embodiment of the present invention is disclosed to include a nonvolatile memory system for controlling erase operations performed on a nonvolatile memory array comprised of rows and columns, the nonvolatile memory array stores digital information organized into blocks with each block having one or more sectors of information and each sector having a user data field and an extension field and each sector stored within a row of the memory array. A controller circuit is coupled to a host circuit and is operative to perform erase operations on the nonvolatile memory array, the controller circuit erases an identified sector of information having a particular user data field and a particular extension field wherein the particular user field and the particular extension field are caused to be erased separately.

Claims

1. A method for operating a non-volatile memory array having a plurality of nonvolatile storage blocks for storing data, each block having one or more user data field and extension field, wherein each block is selectively programmable and erasable wherein blocks having superseded data may not be programmed until erased, the method comprising the steps of:

determining whether any blocks having superseded data remain;

periodically selecting blocks having superseded data for erasure thereof; and

erasing the selected blocks wherein the user data fields of the selected blocks is erased separately from the extension fields of the selected blocks.