Dynamic Word Line Replacement for Row Hammer Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for addressing the row hammer effect in dynamic memory, which causes data errors due to repeated activation of specific word lines, are inadequate, especially in burst type refresh operations and require modifications to memory specifications, leading to usage difficulties.
Innovation Solution
A method that calculates the accessed times of each word line address, identifies aggressor word lines by comparing these times to a threshold, and replaces memory cells of aggressor word lines with backup word lines to prevent data errors, thereby improving data reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional refresh operations are performed to resolve row hammer effect, then data reliability is improved, but device complexity and specification modification requirements increase
Solution Approach 1:
The patent identifies aggressor word lines in advance by monitoring access frequencies and proactively replaces them with backup word lines before data errors occur. This preliminary action prevents the need for complex additional refresh operations during runtime, thereby improving data reliability while avoiding increased device complexity
Solution Approach 2:
The patent creates backup word lines as copies of original word lines. When an aggressor word line is detected, its data is copied to a backup word line, and the backup replaces the original. This copying mechanism resolves the row hammer effect without requiring complex specification modifications or additional refresh operations
2Reliability
If conventional additional refresh operations are used, then data errors are corrected, but the solution cannot be implemented in burst type refresh operations and requires specification modifications
Solution Approach 1:
The patent implements a dynamic replacement mechanism where backup word lines are selectively activated based on real-time access frequency monitoring. The system dynamically identifies aggressor word lines and replaces them with backups only when needed, making the solution adaptable to different refresh operation types including burst type refresh operations without requiring specification modifications
Solution Approach 2:
The patent changes the parameter of word line accessibility by introducing backup word lines that can replace aggressor word lines. This parameter change allows the system to handle different refresh operation types flexibly, as the backup mechanism works uniformly across various refresh scenarios without requiring different specification configurations
Data Source
AI summary
A memory apparatus and a memory accessing method are provided. The memory accessing method includes: calculating an accessed times of each of a plurality of word line addresses; setting each of the corresponding word line addresses as an aggressor word line address by comparing the accessed times of the each of the word line addresses and a threshold accessed times; and setting a backup word line address, and replacing memory cells of the aggressor word line address by memory cells of the backup word line address.