DE10330493A1 - Management of characteristic memory information, especially in flash memory, whereby the characteristic memory information is stored in a defined entry in the memory reconstruction table - Google Patents

Abstract

Method for managing characteristic memory information (CSI) in a non-volatile memory, especially a flash memory, that is written to in sectors and in which deletion is in a block-based manner. The memory has a reconstruction table (RKT) that is cyclically updated. The characterizing memory information is held in a defined entry of the reconstruction table.

Description

The The invention relates to a method for the management of characterizing Memory information in a sector-wise recordable and block by block erasable nonvolatile Memory that contains a reconstruction table for reorganization, the is written cyclically.

The widely used nonvolatile Semiconductor memories (flash memories) are organized in blocks and in sectors, where a block is e.g. consists of 32 sectors with 512 bytes each. The Memory own the property that new information sector by sector written and written only previously deleted sectors can be. The deleting takes place for each a block for all sectors together. Writing a sector in the store takes longer as the read and a delete operation of a block requires a long time, e.g. several milliseconds.

One Method for reorganizing a nonvolatile memory by means of a Reconstruction table is from the unpublished German patent application 10227255.7 known.

in the nonvolatile Memory is reserved one or more blocks of data into which one Reconstruction table is written. This reconstruction table has a defined length from e.g. 128 sectors. In a volatile memory memory for the memory blocks, the administrative records are created in which noted the logical and physical block addresses are, as well as the addresses of the alternative blocks, in the currently written becomes. Now become new memory blocks described or new alternative blocks provided and obsolete assignments from logical to physical Block addresses resolved, an entry is written continuously in the reconstruction table. The respective entry in the reconstruction table contains at least the logical block address, the physical block address of the original memory block as well as the address of the possibly used alternative block.

If now after a power failure a restart of the storage system From the program of the storage controller, the administrative records are volatile Memory memory is initialized empty and then the reconstruction table gone through from the beginning and assignments according to each Entry in the reconstruction table entered into the administrative records. This will be for repeats each entry in the reconstruction table until that End of this table is reached. It is quite possible that Overwritten several assignments several times as they are also updated in the course of the original saves were. But it will be at the end of the restart of the current state the address mappings in the administrative records restored as he before the power failure.

In the described embodiment the reconstruction table is this constructed so that every entry in the table is exactly one sector long, even if not all Bytes of the sector filled are. Since the memory is always written sector by sector, is not Additional expenses for a data preparation required. Even if some space on not used this way, this is due to the size of the whole Memory does not matter. Since all sectors from the current Entry in the table deleted are, without further effort, the next entry directly into the Table written.

There the reconstruction table has a defined length, e.g. 128 entries, will they filled in normal storage mode until almost the end. advantageously, is, if the penultimate entry was written, a reorganization started. This is a note about the reorganization last Entry written in the reconstruction table. Then everyone will Address mappings, as current in the administrative records listed are dissolved and thus a defined ground state established in the administrative records, such as it also initializes at a restart of the system first would.

To a successful reorganization will be a done entry in the Reconstruction table written. This finished entry is advantageously with a count which is incremented during each reorganization and thus the total number the reorganizations of the store since manufacturing indicates.

at every reorganization becomes a new reconstruction table in others memory blocks created. These are taken from the store of deleted memory blocks, either originally deleted or deleted from a background program. The finished entry is written as the first entry in the new reconstruction table. The previous blocks for the Reconstruction table are then released and thus marked, that they are edited by the background program for deletion.

If in the process of reorganization the power fails and yet no new finished entry has been written, it will be restarted the system reboots the reorganization. The reorganization is repeatable as often as you like.

If the finished entry has already been written, but the previous reconstruction table still has not been released, it can happen that during the restart of the system two reorganization tables, the previous and the new, to be found. Then, based on the count in the finished entry the reconstruction table found which is the newer table is, and the reorganization process is continued accordingly. Thus, even in such cases to ensure the correct further operation of the storage system.

In the described method, however, no provision is made characterizing storage information, such as configuration data about the Memory allocation and / or cipher keys to store efficiently. Safe guiding such information is especially with the emergence of so-called Secure digital cards have become important in protected and unprotected Areas are shared.

It Object of the invention, the known method of reorganization from nonvolatile memories to expand so that the characterizing memory information be kept efficient and changed at any time can.

Is solved this task in that the characterizing memory information held in a predetermined entry of the reconstruction table are.

advantageous Embodiments of the invention are specified in the subclaims.

The Reconstruction table is kept in nonvolatile memory and described sectorally. An entry in a sector contains an identifier for the Type of entry and information about the written and deleted memory blocks, off those at a restart of the memory of the current state is reconstructed. An identifier for an entry represents the Done entry. It is used at every reorganization of the storage written the beginning of a new reorganization table. He contains beside Space for Administrative data for the characterizing memory information is used.

The characterizing memory information is various permanent Data describing the distribution and use of the storage. A division creates e.g. a variable border between one protected and an unprotected one Storage area. The image of configuration registers can also be stored in be included in this information. More user data in it can also encryption be for encryption and decryption serve storage areas.

If this characterizing memory information will be changed The new information is provided by a higher-level operating system in a correspondingly marked entry in the reconstruction table noted.

At the Startup of the storage system will be the data from the current finished entry read and possibly followed by in the reconstruction table, Updated corresponding entries.

at a reorganization of the memory is the updated version the characterizing memory information written in the new finished entry.

An advantageous embodiment of the invention is in the 1 described.

1 shows a reconstruction table RKT with 128 entries. The first entry is a done entry, indicated by FE. This entry contains a finished counter FZ the number of reorganizations performed and general management data VD the characterizing memory information CSI.

The normal reconstruction entries are marked with RE and contain the logical block addresses LBA and the memory block addresses SBA and the alternative block addresses ABA of writes in the store. There is also room for general administrative data intended.

One Entry with changed characterizing memory information CSI is marked with SD provided. Also in this entry is space for general administrative data VD created.

The End of a reconstruction table RKT is identified by the entry OE, which may also contain further administrative data.

Claims (7)

A method for managing characterizing memory information (CSI) in a sector-wise writable and block-erasable nonvolatile memory, which for reorganization contains a reconstruction table (RKT) which is cyclically rewritten, characterized in that the characterizing memory information (CSI) in a particular entry of the Rekonstrukti Onktelle (RKT) are held. Method according to claim 1, characterized in that that the particular entry in the Reconstruction Table (RKT) Finished entry (FE) is rewritten after each reorganization. Method according to claim 2, characterized in that that the characterizing memory information (CSI) is management data which are a configuration and / or use of the memory describe. Method according to claim 3, characterized that in the characterizing memory information (CSI) information about protected and unprotected areas of the memory are included. Method according to claim 3, characterized that in the characterizing memory information (CSI) cipher key for the encryption and decryption of storage areas are included. Method according to claim 2, characterized in that that changes the characterizing memory information (CSI) in as such marked entries (SD) of the reconstruction table (RKT). Method according to Claim 6, characterized that with a reorganization of the memory the contents of the marked Entry (SD) in the new finished entry (FE) of the new reconstruction table (RKT) becomes.