US 8,301,825 B2Granted

Method and system for storing logical data blocks into flash-blocks in multiple non-volatile memories which are connected to at least one common data I/O bus

AssigneeThomson Licensing

InventorsJens Peter Wittenburg, Thomas Brune

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Abstract

For recording or replaying in real-time digital HDTV signals very fast memories are required. For storage of streaming HD video data NAND flash memory based systems can be used. However, NAND flash memories have a slow write access, and they have unmasked production defects. Write or read operations can be carried out on complete physical data blocks only, and defect data blocks must not be used by the file system. Logical file system blocks are used which are larger than the physical data blocks. According to the invention the error reporting mechanism of the NAND flash memories is exploited. The video data is not only written to the non-volatile flash memories, but is also written to corresponding buffer slots (LFSB) of a volatile SRAM or DRAM memory operating in parallel. The video data are kept in the volatile memory until the flash memory holding the respective data has reported that its program or write operation succeeded. Once this has taken place, the data within the volatile memory can be overwritten in order to save memory capacity. If the flash memory has reported an error, the respective block (FSBD) of data is marked bad and will not be overwritten until the end of the entire recorded take has been reached. At this time, the marked video data from the volatile memory are copied to spare flash-blocks within the flash memories.

Claims14

Dependent claims

Method for storing logical file system blocks in a storage system that includes:

multiple non-volatile memories which are connected to at least one common data I/O bus, wherein at least a plurality of said non-volatile memories are physically accessed on a memory page basis, where each memory page includes multiple data words, and each one of said at least a plurality of non-volatile memories are logically accessed on a flash-block basis, which where each flash-block includes multiple ones of said memory pages, and wherein a logical file system block is the combination of one flash-block from all non-volatile memories used in said storage system, and
volatile memory means which hold multiple buffer slots each containing a logical file system block;
said method comprising the steps:
storing page data into logical file system blocks of the multiple non-volatile memories and in parallel into corresponding buffer slots in the volatile memory means, in a circular buffer slot access sequence, whereby the respectively used storage capacity of said volatile memory means is smaller than the storage capacity of said non-volatile memories and whereby, after the last free buffer slot has been written, said sequence again starts with overwriting the first buffer slot,
and whereby, if one or more of said non-volatile memories signal that, when recording current page data an error has occurred, the corresponding current buffer slot in said volatile memory means or a related table entry is marked correspondingly and in the following turn or turns of said sequence said marked buffer slot or slots are skipped such that the data stored therein are kept unchanged;
after a take has been recorded, copying flash-block data of said non-volatile memory means that contain erroneous page data into free flash-blocks within the same non-volatile memory, and checking which buffer slots in said volatile memory means or which related table entries are marked and copying corresponding page data from said marked buffer slots of said volatile memory means into the corresponding memory pages of said free flash-blocks in said non-volatile memories.

3 more elements

Storage system for storing logical file system blocks in multiple non-volatile memories which are connected to at least one common data I/O bus, wherein at least a plurality of said non-volatile memories are physically accessed on a memory page basis, where each memory page includes multiple data words, and each one of said at least a plurality of non-volatile memories are logically accessed on a flash-block basis, where each flash-block includes multiple ones of said memory pages, and wherein a logical file system block is the combination of one flash-block from all non-volatile memories used in said storage system, said storage system comprising:

multiple non-volatile memories;
volatile memory means which hold multiple buffer slots each containing a logical file system block;
means for storing page data into flash logical file system blocks of the multiple non-volatile memories and in parallel into corresponding buffer slots in the volatile memory means, in a circular buffer slot access sequence, whereby the respectively used storage capacity of said volatile memory means is smaller than the storage capacity of said non-volatile memories and whereby, after the last free buffer slot has been written, said sequence again starts with overwriting the first buffer slot,
and wherein, if one or more of said non-volatile memories signal that, when recording a current page data an error has occurred, the corresponding current buffer slot in said volatile memory means or a related table entry is marked correspondingly and in the following turn or turns of said sequence said marked buffer slot or slots are skipped such that the data stored therein are kept unchanged;
which means, after a take has been recorded, copy flash-block data of said non-volatile memory means that contain erroneous page data into free flash-blocks within the same non-volatile memory, and check which buffer slots in said volatile memory means or which related table entries are marked, and copy corresponding page data from said marked buffer slots of said volatile memory means into the corresponding memory pages of said free flash-blocks in said non-volatile memories.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/918,164Filed 20 Mar 2006
Priority: EP 0509011115 Apr 2005
Published: US 2009/0043948 A112 Feb 2009
Granted: 30 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G06F 12/0246
Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory: in block erasable memory, e.g. flash memory
G06F 2212/7203
Details relating to flash memory management: temporary buffering, e.g. using volatile buffer or dedicated buffer blocks
G11C 11/005
Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor: comprising combined but…
G11C 16/0483
Using variable threshold transistors, e.g. FAMOS: comprising cells having several storage transistors connected in series