IP Library Granted Patent US 10,943,637
Granted Patent B2
US 10,943,637 · App. 16/234,397 · Granted Mar 9, 2021

Apparatus with a row-hammer address latch mechanism

Inventor: Sadayuki Okuma (Tokyo, JP)
Assignee: Micron Technology, Inc.
G11C11/40611G06F12/0646G06F2212/1008
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Quick Facts
Patent No.
US 10,943,637
App. No.
16/234,397
Granted
Mar 9, 2021
Kind
B2
Abstract

An apparatus includes an address bus configured to convey a command address; a primary address latch connected to the address bus and configured to latch a first address; a primary counter connected to the primary address latch and configured to track a primary count value when the command address matches the first address; and a secondary counter connected to the primary counter and configured to update a secondary count value when the primary count value reaches a primary threshold.

Claims (40)

1. An apparatus, comprising:

an address bus configured to convey a command address;

a primary address latch connected to the address bus and configured to latch a first address;

a primary counter connected to the primary address latch and configured to track a primary count value when the command address matches the first address; and

a secondary counter connected to the primary counter and configured to update a secondary count value when the primary count value reaches a primary threshold;

wherein the primary and secondary count values are configured to control different refresh operations associated with the command address.

2. The apparatus of claim 1 , further comprising:

a primary address calculator configured to calculate a primary address of a primary victim word line when the primary count value reaches the primary threshold;

wherein:

the first address corresponds to an aggressor word line; and

the primary victim word line is adjacent to the aggressor word line.

3. The apparatus of claim 2 , further comprising a refresh circuit connected to the primary counter and the secondary counter and configured to execute a primary row hammer refresh operation based on the primary address to recharge the primary victim word line when the primary count value reaches the primary threshold.

4. The apparatus of claim 2 , further comprising:

a secondary address calculator configured to calculate a secondary address of a secondary victim word line when the secondary count value reaches a secondary threshold; and

wherein:

the secondary victim word line is adjacent to the primary victim word line.

5. The apparatus of claim 4 , further comprising a refresh circuit connected to the primary counter and the secondary counter and configured to execute:

a primary row hammer refresh (RHR) operation based on the primary address to recharge the primary victim word line when the primary count value reaches the primary threshold; and

a secondary row hammer refresh (RHR) operation based on the secondary address to recharge the secondary victim word line when the secondary count value reaches the secondary threshold.

6. The apparatus of claim 5 , wherein the refresh circuit is configured to execute the primary RHR operation, the secondary RHR operation, or a combination thereof in response to a refresh command.

7. The apparatus of claim 4 , wherein the secondary threshold is greater than the primary threshold.

8. The apparatus of claim 4 , further comprising:

a refresh control logic configured to identify a row hammer condition when the primary count value reaches the primary threshold;

wherein:

the primary counter is configured to track a number of times the first address is activated, deactivated, or a combination thereof before the primary address is refreshed; and

the secondary counter is configured to track a number of times the first address is activated, deactivated, or a combination thereof before the secondary address is refreshed.

9. The apparatus of claim 8 , further comprising:

a scheduled refresh (CBR) counter connected to the address bus and configured to generate a scheduled refresh (CBR) address according to a schedule to refresh one or more word lines associated with the CBR address; and

the refresh control logic is configured to:

reset the primary count value when the CBR address matches the primary address, and

reset the secondary count value when the CBR address matches the secondary address.

10. An apparatus comprising:

an address bus;

at least one first address latch configured to temporarily latch a first address;

at least one first counter configured to update its count value each time an address conveyed through the address bus matches the first address; and

at least one second counter configured to update its count value each time the at least one first count reaches to a first predetermined value;

wherein the count values of the first and second counters are configured to control different refresh operations associated with the address.

11. The apparatus of claim 10 , wherein when the at least one first counter has reached the first predetermined value, a second address adjacent to the first address is configured to be subject to a first refresh operation.

12. The apparatus of claim 11 , wherein when the at least one second counter has reached a second predetermined value, a third address adjacent to the second address is configured to be subject to a second refresh operation.

13. The apparatus of claim 12 , wherein each of the first and second refresh operations is performed in response to a refresh command.

Assignments (5)
RELEASE OF SECURITY INTEREST Recorded Nov 15, 2019
From: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 051041/0317 →
RELEASE OF SECURITY INTEREST Recorded Oct 14, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 050724/0392 →
SUPPLEMENT NO. 12 TO PATENT SECURITY AGREEMENT Recorded Apr 19, 2019
From: MICRON TECHNOLOGY, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
Reel/Frame 048948/0677 →
SUPPLEMENT NO. 3 TO PATENT SECURITY AGREEMENT Recorded Apr 19, 2019
From: MICRON TECHNOLOGY, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 048951/0902 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 27, 2018
From: OKUMA, SADAYUKI
To: MICRON TECHNOLOGY, INC.
Reel/Frame 047863/0543 →