Controller Signaling for Dynamic Memory Refresh Scheduling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing memory systems lack precise control over the scheduling of sequential and targeted refresh operations, leading to inefficient refresh management and potential over-refreshing, which increases downtime.

Innovation Solution

A controller is designed to issue specific refresh commands, allowing for precise control over when sequential and targeted refresh operations are performed. The controller tracks access patterns and issues refresh management commands based on access counts, enabling targeted refresh operations for aggressor rows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the controller performs refresh operations without precise control over scheduling, then the memory cells are refreshed periodically, but this leads to over-refreshing and increases downtime

Engineering Contradiction:

Improvememory data integrityVSAvoiddowntime

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically adjusts refresh operation scheduling based on real-time access patterns. The controller monitors which rows are frequently accessed (aggressors) and adjusts refresh timing accordingly, transitioning from static periodic refresh to dynamic on-demand refresh based on actual memory access behavior

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller receives feedback about memory access patterns from the memory device and uses this information to adjust refresh scheduling. By monitoring access counts and identifying aggressor rows, the system feedbacks control signals to optimize refresh timing and reduce unnecessary refresh operations

Inventive Principle:

Principle #23Feedback

2Reliability

If targeted refresh operations are performed for aggressor rows, then information decay is addressed more effectively, but this requires more complex control signaling from the controller

Engineering Contradiction:

Improveinformation retentionVSAvoidcontroller signaling complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The refresh operation is segmented into different types: sequential refresh for all rows and targeted refresh for specific aggressor rows. The controller divides the refresh management task into manageable components, controlling which rows receive which type of refresh based on access patterns

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different refresh strategies are applied to different rows based on their access characteristics. Frequently accessed rows (aggressors) receive targeted refresh operations, while less accessed rows follow the standard periodic refresh schedule, optimizing resource allocation based on local row behavior

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250173255A1Apparatuses and methods for controller signaling of refresh operations

Publication Date: 2025.05.29 MICRON TECHNOLOGY INC

AI summary

Apparatuses and methods for controller signaling of refresh operations. A memory may receive a first or a second type of refresh command. Responsive to the first type of refresh command a first type of refresh operation (e.g., a sequential refresh operation) may be performed. Responsive to the second type of refresh operation a second type of refresh operation (e.g., a targeted refresh operation) may be performed. This may allow the controller to have greater control over the timing of different types of refresh operation in the memory