Memory device having a write-back cache storing cache data and scrub data
AssigneeMicron Technology, Inc.
InventorsChristophe Vincent Antoine Laurent, Ferdinando Bedeschi
Life of this patent
Estimating the term…
Abstract
Systems, methods, and apparatus for a memory device that stores a scrub list in a cache used to reduce data traffic to and from a memory array. In one approach, the cache merges the scrub list with cache data. Data in the scrub list can be identified and distinguished from the cache data by adding a one-bit scrub flag to each data entry in the merged cache. In this merged approach, the cache data shares the same memory as the scrub list. Read data that has an error is saved temporarily in this merged cache until the correct value for the data is written back into the memory array.
Claims18
An apparatus comprising:
- a cache;
- and
- a memory controller configured to:
- in response to receiving a first read command requesting a second data set, determine that the second data set is not stored in the cache, and read the second data set from a memory array;
- in response to determining that the second data set read from the memory array has an error, correct the second data set, store the corrected second data set in the cache, and set a flag for the second data set;
- and
- in response to receiving a second read command requesting the second data set, determine that the second data set is stored in the cache, determine the flag is set, write the corrected second data set from the cache to the memory array, and read the corrected second data set from the cache.
An apparatus comprising:
- a cache;
- and
- a controller configured to:
- determine that a first data set read from a memory array has an error, correct the first data set, store the corrected first data set in the cache, and set a scrub flag for the first data set;
- receive a read command from a host device, the read command requesting the first data set;
- in response to receiving the read command, determine the first data set is stored in the cache and that the scrub flag for the first data set is set;
- in response to determining that the scrub flag is set, write back the corrected first data set from the cache to the memory array;
- read the corrected first data set from the cache;
- and
- send the corrected first data set to the host device.
A method comprising:
- in response to determining that a first data set read from a memory array has an error, correcting the first data set;
- storing the corrected first data set in a scrub area of a cache memory;
- receiving a request to read the first data set;
- in response to determining that the first data set is stored in the scrub area, writing back the corrected first data set from the scrub area to the memory array;
- and
- providing the corrected first data set from the scrub area in reply to the request.
Dependencies are inferred from the claim text.