Data storage device and method for inferring a read threshold using a time tag determination
AssigneeSanDisk Technologies LLC
InventorsDavid Avraham, Ariel Navon, Alexander Bazarsky, Eran Sharon
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Abstract
A data storage device has an inference engine that can infer a read threshold based on a non-linear function of inputs that reflect current memory and data conditions. The read threshold can be used in reading a wordline in the memory. Using a machine-learning-based approach to infer a read threshold can provide significant improvement in read threshold accuracy, which can reduce bit error rate and also improve latency, throughput, power consumption, and quality of service.
Claims17
In a data storage device comprising a memory, a method comprising:
- using firmware in the data storage device to infer a read threshold to use in reading a wordline in the memory, wherein the read threshold is inferred:
- prior to the data storage device receiving a read command from a host that causes the wordline to be read;
- only during a time and temperature update;
- and
- based only on one or more inputs available during the time and temperature update, wherein a wordline number of the wordline is not one of the one or more inputs;
- and
- in response to receiving the read command from the host:
- looking up the wordline number in a pre-calibrated wordline zoning table comprising a plurality of predefined correction values associated with a respective plurality of wordline numbers;
- modifying the inferred read threshold based on a correction value associated with the wordline number in the pre-calibrated wordline zoning table;
- and
- using the modified inferred read threshold to read the wordline.
A data storage device comprising:
- a memory;
- and
- a processor configured to execute firmware to:
- infer a read threshold to use to read a wordline in the memory, wherein the read threshold is inferred:
- prior to the data storage device receiving a read command from a host that causes the wordline to be read;
- only during a time and temperature update;
- and
- based only on one or more inputs available during the time and temperature update, wherein a wordline number of the wordline is not one of the one or more inputs;
- and
- in response to receiving the read command from the host:
- look up the wordline number in a pre-calibrated wordline zoning table comprising a plurality of predefined correction values associated with a respective plurality of wordline numbers;
- modify the inferred read threshold based on a correction value associated with the wordline number in the pre-calibrated wordline zoning table;
- and
- use the modified inferred read threshold to read the wordline.
A data storage device comprising:
- a memory;
- and
- means for:
- using firmware in the data storage device to infer a read threshold to use in reading a wordline in the memory, wherein the read threshold is inferred:
- prior to the data storage device receiving a read command from a host that causes the wordline to be read;
- only during a time and temperature update;
- and
- based only on one or more inputs available during the time and temperature update, wherein a wordline number of the wordline is not one of the one or more inputs;
- and
- in response to receiving the read command from the host:
- looking up the wordline number in a pre-calibrated wordline zoning table comprising a plurality of predefined correction values associated with a respective plurality of wordline numbers;
- modifying the inferred read threshold based on a correction value associated with the wordline number in the pre-calibrated wordline zoning table;
- and
- using the modified inferred read threshold to read the wordline.
Dependencies are inferred from the claim text.