Memory Device Row Hammer Defense via Segment Masking
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Solution Overview
Problem
Existing memory devices are vulnerable to row hammer attacks, where malicious actors use decoy addresses to evict legitimate row hammer addresses from storage, leading to data corruption and intermittent failures due to repeated accesses to a single memory cell row, which existing management systems struggle to defend against effectively.
Innovation Solution
The implementation of a memory device with a refresh control circuit that generates a row hammer segment signal, a refresh segment signal, and a segment mask signal to selectively unmask and refresh masked memory cell regions, allowing for targeted and periodic refresh operations to defend against row hammer attacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If decoy row hammer addresses are used to interfere with row hammer management, then the complexity of row hammer management increases, but the reliability of memory protection decreases
Solution Approach 1:
The memory device divides the memory cell array into multiple segments, with each segment independently manageable. This segmentation allows the system to track and refresh specific segments affected by row hammer attacks while ignoring decoy addresses targeting other segments, thereby maintaining protection reliability without managing all addresses uniformly
Solution Approach 2:
A segment mask signal acts as an intermediary between the address storage and the row hammer management circuitry. This mask signal filters out decoy addresses by preventing them from triggering refresh operations on non-vulnerable segments, while still allowing legitimate row hammer addresses to be processed correctly
2Reliability
If all memory cell rows are refreshed continuously, then the reliability of data integrity improves, but the energy consumption increases
Solution Approach 1:
Instead of uniformly refreshing all memory cell rows, the system applies refresh operations selectively to specific segments based on their vulnerability status. Segments identified as vulnerable to row hammer attacks receive continuous refresh protection, while non-vulnerable segments undergo refresh only when necessary, optimizing energy consumption while maintaining data integrity where needed
Solution Approach 2:
The refresh operation is implemented periodically rather than continuously for all segments. The system monitors segment vulnerability status and triggers refresh operations at appropriate intervals based on actual risk levels, reducing unnecessary energy consumption while ensuring protection when row hammer attacks are detected
3Productivity
If masked memory cell regions are excluded from refresh operations, then the productivity of refresh operations improves, but the reliability of data protection decreases
Solution Approach 1:
The segment mask signal is dynamically adjustable rather than fixed. The system can modify which segments are masked based on real-time detection of row hammer attacks, allowing previously masked segments to be unmasked when no longer vulnerable, and newly vulnerable segments to be masked. This dynamic adjustment maintains refresh operation efficiency while ensuring data protection reliability adapts to changing threat conditions
Data Source
AI summary
Provided is a memory device including a memory cell array including a plurality of memory cell rows, the plurality of memory cell rows being grouped into a plurality of segments, a row decoder connected to the plurality of memory cell rows, and a refresh control circuit configured to generate a refresh control signal for controlling a refresh operation on the plurality of memory cell rows.