Method and apparatus for block-oriented memory management provided in smart card controllers
AssigneeAustria Card Plastikkarten und Ausweissysteme GmbH
InventorRainer Nase
Life of this patent
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Abstract
A method for memory management in smart card controllers by writing of data into a data space in a persistent memory is described. In order to save memory space the persistent memory is split into blocks with fixed data length having logical block numbers; whereby the size of blocks is selected such that it corresponds to the physical size of the pages of the EEPROM memory existing on the card. Fragmented blocks are used by comprising segments being independent from each other, whereby these segments are part of different data fields. A Block Allocation Table (BAT) is used in order to distinguish the physical place of the block in memory from the logical block number and to address different segments in the block.
Claims14
A method for memory management in smart card controllers or similar restricted hardware environment by writing of data into a data space in a persistent memory, said method comprising steps of:
- a) splitting the persistent memory into blocks with fixed data length having logical block numbers (LBN);
- b) selecting the size of blocks as such that it is equal to—or equivalent to an integer ratio of—the length of a page in EEPROM to the physical size of the pages of the EEPROM memory existing on the card;
- c) providing a Block Allocation Table (BAT) in order to calculate the physical place of the block in memory from the logical block number;
The method according to 1, wherein a secure write mechanism is accomplished by replacing individual memory blocks by each other.
A device with a persistent memory and a block structure comprising:
- a) a memory managing system using a block oriented memory structure;
- b) blocks with the same, length and identifying them by their logical block number (LBN);
- c) a block allocation table (BAT) to resolve the logical block number to a physical block number (PBN) and its physical address;
Dependencies are inferred from the claim text.