Back to results
US 2009/0276586 A1Published application
Wrap-around sequence numbers for recovering from power-fall in non-volatile memory
AssigneeIntel Corporation
InventorsRobert Royer, Han H. Chau, Sanjeev N. Trika
Life of this patent
Estimating the term…
Abstract
Incrementing sequence numbers in the metadata of non-volatile memory is used in the event of a resume from power fail to determine which data in the memory is current and valid, and which data is not. To reduce the amount of metadata space consumed by these sequence numbers, the numbers are permitted to be small enough to wrap around when the maximum value is reached. Two different techniques are disclosed to keep this wrap around condition from causing ambiguity in the relative values of the sequence numbers.
Claims25
An apparatus, comprising:
- a non-volatile memory;
- and
- a memory controller to control reads, writes, and erases of contents of the memory, and to write a sequence number value into metadata of each sub-unit of a block if data is written into the sub-unit;
- wherein the memory controller is to increment the sequence number value each time a new sub-unit is written into, and is to wrap the sequence number around to a minimum value after a maximum value of the sequence number is reached.
1 more element
A method comprising:
- incrementing a counter to generate a sequence number for writing into metadata in a non-volatile memory, each time data is to be written into a new page of the non-volatile memory;
- wrapping the counter back to the counter's minimum value resultant to the counter reaching its maximum value;
- and
- using the sequence numbers written into the metadata of multiple ones of the pages to determine which pages are current and which pages are stale, resultant to recovering from a power fail.
1 more element
An article comprising
- a tangible machine-readable medium that contains instructions, which when executed by one or more processors result in performing operations comprising:
- incrementing a counter to generate a sequence number for writing into metadata in a non-volatile memory, each time data is to be written into a new page of the non-volatile memory;
- wrapping the counter back to the counter's minimum value resultant to the counter reaching its maximum value;
- using the sequence numbers written into the metadata of multiple ones of the pages to determine which pages are current and which pages are stale, resultant to recovering from a power fail.
1 more element
Dependencies are inferred from the claim text.