Flash memory data correction and scrub techniques
DCFirst Claim
1. A method of operating a re-programmable non-volatile memory system, comprising:
- receiving commands from a host and executing the received commands,monitoring patterns of activity of the host, at least in connection with the received commands, andupon identifying a first pattern of host activity, a housekeeping operation is enabled to be executed, the housekeeping operation being of a type not required for execution of one of the commands received from the host, orupon identifying a second pattern of host activity different from the first pattern, execution of the housekeeping operation is not enabled.
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Litigations
1 Petition
Accused Products
Abstract
In order to maintain the integrity of data stored in a flash memory that are susceptible to being disturbed by operations in adjacent regions of the memory, disturb events cause the data to be read, corrected and re-written before becoming so corrupted that valid data cannot be recovered. The sometimes conflicting needs to maintain data integrity and system performance are balanced by deferring execution of some of the corrective action when the memory system has other high priority operations to perform. In a memory system utilizing very large units of erase, the corrective process is executed in a manner that is consistent with efficiently rewriting an amount of data much less than the capacity of a unit of erase.
159 Citations
15 Claims
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1. A method of operating a re-programmable non-volatile memory system, comprising:
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receiving commands from a host and executing the received commands, monitoring patterns of activity of the host, at least in connection with the received commands, and upon identifying a first pattern of host activity, a housekeeping operation is enabled to be executed, the housekeeping operation being of a type not required for execution of one of the commands received from the host, or upon identifying a second pattern of host activity different from the first pattern, execution of the housekeeping operation is not enabled. - View Dependent Claims (2, 3, 4)
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5. A method of operating a re-programmable non-volatile memory system, comprising:
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note when a housekeeping operation not required for execution of a command received from a host has been asserted, determine at least one parameter of activity of the host, and if the determined at least one parameter meets at least one predefined condition, execution of the housekeeping operation is not enabled, but if the determined at least one parameter does not meet the predefined condition, the housekeeping operation is enabled for execution. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A memory system adapted to be removably connected with a host system, comprising:
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an array of re-programmable non-volatile memory cells organized into blocks of memory cells wherein the memory cells of the individual blocks are simultaneously erasable, a controller including a microprocessor that operates to; note when a housekeeping operation not required for execution of a command received from a host has been asserted, determine at least one parameter of activity of the host, and if the detetinined at least one parameter meets at least one predefined condition, execution of the housekeeping operation is not enabled, but if the determined at least one parameter does not meet the predefined condition, the housekeeping operation is enabled for execution. - View Dependent Claims (12, 13, 14, 15)
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Specification