US 2019/0103164 A1 · PREEMPTIVE IDLE TIME READ SCANS

Abstract

Devices and techniques for initiating and controlling preemptive idle time read scans in a flash based storage system are disclosed. In an example, a memory device includes a NAND memory array and a memory controller to schedule and initiate read scans among multiple locations of the memory array, with such read scans being preemptively triggered during an idle (background) state of the memory device, thus reducing host latency during read and write operations in an active (foreground) state of the memory device. In an example, the optimization technique includes scheduling a read scan operation, monitoring an active or idle state of host IO operations, and preemptively initiating the read scan operation when entering an idle state, before the read scan operation is scheduled to occur. In further examples, the read scan may preemptively occur based on time-based scheduling, frequency-based conditions, or event-driven conditions triggering the read scan.

Claims31

Dependent claims

A memory device, comprising:

a NAND memory array;
and
a memory controller operably coupled to the memory array, the memory controller to perform operations comprising:
scheduling a read scan operation on the memory array to occur upon a scheduled condition, wherein the read scan operation is to sample data at multiple locations of the memory array by performing reads at the multiple locations;
monitoring an operational state of the memory array, the operational state of the memory array including an active state corresponding to performing operations initiated from a host, and an idle state corresponding to an absence of operations initiated from the host;
and
initiating the read scan operation in response to the operational state of the memory array entering the idle state, wherein the read scan operation is initiated to preemptively occur before the scheduled condition.

4 more elements

A method for performing preemptive read scans in a memory device, the method comprising a plurality of operations performed by a memory controller upon a NAND memory array of the memory device, with the operations comprising:

scheduling a read scan operation on the memory array to be conducted upon a scheduled condition, wherein the read scan operation is to sample data at multiple locations of the memory array by performing reads at the multiple locations, and wherein the reads are performed with different read voltages among the multiple locations;
monitoring an operational state of the memory array, the operational state of the memory array including an active state corresponding to performing operations initiated from a host, and an idle state corresponding to an absence of operations initiated from the host;
and
initiating the read scan operation in response to the operational state of the memory array entering the idle state, wherein the read scan operation is initiated to preemptively occur before the scheduled condition.

1 more element

A device readable storage medium, that provides instructions that, when executed by a memory controller of a memory device, perform preemptive read scans on a NAND memory array of the memory device, wherein the instructions cause the controller to perform operations comprising:

scheduling a read scan operation on the memory array to be conducted at a scheduled condition, wherein the read scan operation is to sample data at multiple locations of the memory array by performing reads at the multiple locations, and wherein the reads are performed with different read voltages among the multiple locations;
monitoring an operational state of the memory array, the operational state of the memory array including an active state corresponding to performing operations initiated from a host, and an idle state corresponding to an absence of operations initiated from the host;
and
initiating the read scan operation in response to the operational state of the memory array entering the idle state, wherein the read scan operation is initiated to preemptively occur before the scheduled condition.

1 more element

Dependencies are inferred from the claim text.

Preemptive idle time read scans

Life of this patent

Preemptive idle time read scans

Life of this patent

Abstract

Claims31