# US 12,223,995 B2 · Adaptive memory registers

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- Number: US 12,223,995 B2
- Document ID: US12223995B2
- Status: Granted
- Kind: B2
- Application number: 17/823,407
- Filed: 2022-08-30
- Published: 2024-02-29
- Granted: 2025-02-11
- Earliest claimed: 2022-08-30
- Assignees: Micron Technology, Inc.
- Applicants: Micron Technology, Inc.
- Inventors: John Christopher Sancon; Kang-Yong Kim; Yang Lu; Hyun Yoo Lee
- Web page: https://patentgrep.com/patent/US12223995B2

## CPC

- G11C 11/40618: {Refresh operations over multiple banks or interleaving}
- G11C 11/40622: {Partial refresh of memory arrays}
- G11C 11/40615: {Internal triggering or timing of refresh, e.g. hidden refresh, self refresh, pseudo-SRAMs}
- G11C 11/4096: Input/output [I/O] data management or control circuits, e.g. reading or writing circuits, I/O drivers or bit-line switches
- G11C 5/04: Supports for storage elements {, e.g. memory modules}; Mounting or fixing of storage elements on such supports
- G11C 8/12: Group selection circuits, e.g. for memory block selection, chip selection, array selection
- G11C 11/40611: {External triggering or timing of internal or partially internal refresh operations, e.g. auto-refresh or CAS-before-RAS triggered refresh}
- G11C 2211/4067: Refresh in standby or low power modes
- G11C: STATIC STORES (semiconductor memory devices H10B)

## Abstract

Described apparatuses and methods relate to adaptive memory registers for a memory system that may support a nondeterministic protocol. To help manage power-delivery networks in a memory system, a device includes logic that can write values to memory registers associated with memory blocks of a memory array. The values indicate whether an associated memory block has been refreshed within a refresh interval. Other logic can read the registers to determine whether a block has been refreshed. The device also includes logic that can access data indicating a row address that was most recently, or is next to be, refreshed and write values representing the address to another register. The register can be read by other logic to determine whether a wordline potentially affected by an activation-based disturb event is near to being refreshed. These techniques can reduce the number of refresh operations performed, saving power and reducing costs.

## Claims

### Claim 1

An apparatus comprising:
a memory array;
a refresh counter configured to store at least a portion of an address indicative of a refresh operation for a row of the memory array;
at least one memory register; and
logic configured to:
access the refresh counter;
write values to respective entries of the at least one memory register, the values representing the at least a portion of the address; and
write other values to respective entries of the at least one memory register, the other values representing at least a portion of another address indicative of another refresh operation for another row of the memory array, based on a determination that the refresh counter has incremented.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein:
the at least a portion of the address corresponds to a row of the memory array;
that apparatus comprises a memory device; and
the memory device comprises the memory array, the refresh counter, the at least one memory register, and the logic.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the logic is further configured to write the values that represent the at least a portion of the address before the refresh counter takes on another value.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the at least a portion of the address corresponds to a row for which the refresh operation was most recently completed.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the at least a portion of the address corresponds to a row for which a next refresh operation will be performed.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the at least a portion of the address corresponds to a row for which the refresh operation is in-progress.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the at least one memory register comprises at least a portion of a mode register.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the at least one memory register is readable by other logic coupled to the apparatus.

### Claim 9

A method comprising:
reading from at least one memory register, by a logic circuit configured to be coupled to a memory device that includes multiple memory blocks, at least a portion of an address associated with the multiple memory blocks, the at least a portion of the address corresponding to a refresh operation for a row of the multiple memory blocks;
determining a quantity of row addresses between the at least a portion of the address and another row address included on a list of row addresses related to activation-based refresh operations; and
adjusting the list of row addresses related to the activation-based refresh operations based on the quantity and a threshold value.

### Claim 10 (depends on 9)

The method of claim 9, further comprising removing the other row address from the list, based on a determination that the quantity is less than the threshold value.

### Claim 11 (depends on 9)

The method of claim 9, further comprising retaining the other row address on the list, based on a determination that the quantity is greater than the threshold value.

### Claim 12 (depends on 9)

The method of claim 9, further comprising transmitting a signal indicative of a command to perform an activation-based refresh operation for the other row address, based on a determination that the quantity is greater than the threshold value.

### Claim 13 (depends on 9)

The method of claim 9, further comprising reading the at least a portion of the address using a mode register read command.

### Claim 14 (depends on 9)

The method of claim 9, wherein the at least a portion of the address associated with the multiple memory blocks comprises a partial row address that corresponds to at least one row of the multiple memory blocks.

### Claim 15 (depends on 9)

The method of claim 9, wherein the multiple memory blocks comprise multiple memory banks of a memory component.

### Claim 16 (depends on 15)

The method of claim 15, wherein the memory component comports with at least one low-power double data rate (LPDDR) memory standard.

### Claim 17 (depends on 9)

The method of claim 9, wherein activation-based refresh operations comprise refresh operations that are based on an amount of activation commands issued to the multiple memory blocks exceeding a threshold quantity.

### Claim 18 (depends on 9)

The method of claim 9, further comprising:
reading, by the logic circuit, the at least a portion of the address associated with the multiple memory blocks from the at least one memory register in response to an activation-based refresh counter reaching an activation threshold.

### Claim 19 (depends on 9)

The method of claim 9, wherein the logic circuit and the memory device are included in a device that operates in compliance with at least one Compute Express Link (CXL) standard.

### Claim 20

An apparatus comprising:
logic configured to be coupled to at least one memory array, the logic configured to:
read, from at least one memory register associated with the memory array, values that represent at least a portion of a row address of the memory array, the at least a portion of the row address corresponding to a refresh operation for a row of the memory array;
determine a quantity of row addresses between the at least a portion of the row address and another row address included on a list of row addresses related to activation-based refresh operations; and
adjust the list of row addresses related to the activation-based refresh operations, based on the quantity and a threshold value.

### Claim 21 (depends on 20)

The apparatus of claim 20, wherein the logic is further configured to remove the other row address from the list, based on a determination that the quantity is less than the threshold value.

### Claim 22 (depends on 20)

The apparatus of claim 20, wherein the logic is further configured to retain the other row address on the list, based on a determination that the quantity is greater than the threshold value.

### Claim 23 (depends on 20)

The apparatus of claim 20, wherein the logic is further configured to transmit a signal indicative of a command to perform an activation-based refresh operation for the other row address, based on a determination that the quantity is greater than the threshold value.

### Claim 24 (depends on 20)

The apparatus of claim 20, wherein the at least one memory register comprises at least a portion of a mode register.

### Claim 25 (depends on 20)

The apparatus of claim 20, wherein the logic is further configured to read the values from the memory register using a mode register read command.

### Claim 26 (depends on 20)

The apparatus of claim 20, wherein the memory array comports with at least one low-power double data rate (LPDDR) memory standard.

### Claim 27 (depends on 20)

The apparatus of claim 20, further comprising:
the at least one memory array;
an interface configured to be coupled to a host device via an interconnect; and
a link controller coupled to the interface, the link controller configured to communicate with the host device.

### Claim 28 (depends on 27)

The apparatus of claim 27, wherein the interconnect is configured to comport with at least one Compute Express Link (CXL) standard.

### Claim 29 (depends on 27)

The apparatus of claim 27, wherein the link controller comprises a Compute Express Link (CXL) controller.

### Claim 30 (depends on 27)

The apparatus of claim 27, wherein the apparatus comprises a Compute Express Link (CXL) device.

### Claim 31 (depends on 20)

The apparatus of claim 20, wherein the logic is further configured to read the values that represent at least a portion of the address associated with the memory array in response to an activation-based refresh counter reaching an activation threshold.

### Claim 32

An apparatus, comprising:
a memory array including multiple memory blocks;
at least one memory register; and
logic circuitry configured to:
determine which memory blocks of the multiple memory blocks have been refreshed within a current refresh interval; and
write values to respective entries of the at least one memory register associated with respective memory blocks of the multiple memory blocks, the values indicative of whether the respective memory blocks have been refreshed within the current refresh interval.

### Claim 33 (depends on 32)

The apparatus of claim 32, wherein the logic circuitry is further configured to determine that a portion of the multiple memory blocks has been refreshed within the current refresh interval, and wherein the values indicate the respective memory blocks that have been refreshed within the current refresh interval.

### Claim 34 (depends on 32)

The apparatus of claim 32, wherein the logic circuitry is further configured to determine that a portion of the multiple memory blocks has not been refreshed within the current refresh interval, and wherein the values indicate the respective memory blocks that have not been refreshed within the current refresh interval.

### Claim 35 (depends on 32)

The apparatus of claim 32, wherein the logic circuitry is further configured to:
determine that all of the multiple memory blocks have been refreshed within the current refresh interval, and wherein the values indicate that, for another refresh interval after the current refresh interval, none of the multiple memory blocks have been refreshed.

### Claim 36 (depends on 32)

The apparatus of claim 32, wherein the logic circuitry is further configured to write the values to the respective entries of the at least one memory register before the memory array receives a signal indicative of a command to execute refresh operations within a next refresh interval.

### Claim 37 (depends on 32)

The apparatus of claim 32, wherein an entry of the respective entries comprises a bit stored in the at least one memory register.

### Claim 38 (depends on 32)

The apparatus of claim 32, wherein the multiple memory blocks comprise multiple banks of the memory array.

### Claim 39 (depends on 32)

The apparatus of claim 32, wherein the at least one memory register comprises at least a portion of a mode register.

### Claim 40 (depends on 32)

The apparatus of claim 32, wherein the at least one memory register is readable by other logic coupled to the apparatus.

### Claim 41

A method comprising:
determining, by a logic circuit configured to be coupled to multiple memory blocks of a memory device, that at least some of the multiple memory blocks are to be refreshed during a current refresh interval;
reading values from at least one memory register associated with respective memory blocks of the multiple memory blocks; and
determining a portion of the multiple memory blocks that has not been refreshed within the current refresh interval, based on the values.

### Claim 42 (depends on 41)

The method of claim 41, further comprising:
transmitting a signal indicative of a command to execute refresh operations for the portion of the multiple memory blocks that has not been refreshed within the current refresh interval.

### Claim 43 (depends on 41)

The method of claim 41, further comprising: reading the values from at least a portion of a mode register associated with respective memory blocks of the multiple memory blocks using a mode register read command.

### Claim 44 (depends on 41)

The method of claim 41, wherein the multiple memory blocks comprise multiple memory banks of the memory device.

### Claim 45 (depends on 41)

The method of claim 41, wherein the memory device comports with at least one low-power double data rate (LPDDR) memory standard.

### Claim 46 (depends on 41)

The method of claim 41, further comprising:
reading, by the logic circuit, the values from the at least one memory register associated with respective memory blocks of the multiple memory blocks in response to a determination that:
a timing-based refresh operation is required to conform to one or more memory operations standards; or
a refresh operation is required based on entry into, or exit from, a self-refresh mode.

### Claim 47 (depends on 41)

The method of claim 41, wherein the logic circuit and the memory device are included in a device that operates in compliance with at least one Compute Express Link (CXL) standard.

### Claim 48

An apparatus comprising:
a logic circuit configured to be coupled to at least one memory array including multiple memory blocks, the logic circuit configured to:
determine that at least some of the multiple memory blocks are to be refreshed during a current refresh interval;
read values of bits stored in at least one memory register associated with respective blocks of the multiple memory blocks;
determine a portion of the multiple memory blocks that has not been refreshed within the current refresh interval, based on the values of the bits; and
transmit a signal indicative of a command to execute refresh operations for the portion of the multiple memory blocks that has not been refreshed within the current refresh interval.

### Claim 49 (depends on 48)

The apparatus of claim 48, wherein the at least one memory register associated with respective memory blocks of the multiple memory blocks comprises at least a portion of a mode register associated with the respective memory blocks of the multiple memory blocks.

### Claim 50 (depends on 48)

The apparatus of claim 48, wherein the at last one memory array comports with at least one low-power double data rate (LPDDR) memory standard.

### Claim 51 (depends on 48)

The apparatus of claim 48, wherein the multiple memory blocks comprise multiple memory banks.

### Claim 52 (depends on 48)

The apparatus of claim 48 further comprising:
the at least one memory array;
an interface configured to couple to a host device via an interconnect; and
a link controller coupled to the interface, the link controller configured to communicate with the host device.

### Claim 53 (depends on 52)

The apparatus of claim 52, wherein the interconnect is configured to comport with at least one Compute Express Link (CXL) standard.

### Claim 54 (depends on 52)

The apparatus of claim 52, wherein the apparatus comprises a Compute Express Link (CXL) device.

### Claim 55 (depends on 48)

The apparatus of claim 48, wherein the logic circuit is further configured to read the values of the bits in response to a determination that:
a timing-based refresh operation is required to conform to one or more memory operations standards; or
a refresh operation is required based on entry into, or exit from, a self-refresh mode.