CAM Row Hammer Refresh with Multi-Phase Address Sampling
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Solution Overview
Problem
Conventional row hammer refresh methods for content addressable memory devices capture only one row hammer address per refresh interval, leading to lengthy 'no sampling periods and reduced detection efficiency due to flag-lock mechanisms and burst refresh modifications.
Innovation Solution
Divide the row hammer refresh interval into multiple phases, randomly capturing and storing unique row hammer addresses in address registers, allowing for multiple addresses to be refreshed consecutively at the end of the interval, thereby enhancing detection and reducing 'no sampling periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional row hammer refresh methods capture only one row hammer address per refresh interval, then the refresh operation is simple, but the detection efficiency is reduced and lengthy no sampling periods occur
Solution Approach 1:
The patent segments the refresh interval into multiple phases (first phase, second phase, third phase, fourth phase) and captures row hammer addresses in each phase separately. This segmentation allows multiple addresses to be captured within the same refresh interval, eliminating lengthy no sampling periods and improving detection efficiency without requiring a complete redesign of the refresh mechanism.
2Measurement precision
If multiple row hammer addresses are captured and refreshed within the same interval, then detection efficiency improves, but device complexity increases
Solution Approach 1:
The patent implements periodic action by dividing the refresh interval into multiple phases and performing address capture operations periodically in each phase. This structured periodic approach allows multiple addresses to be captured systematically while maintaining a regular, predictable refresh rhythm, thereby improving detection efficiency without introducing chaotic complexity into the device operation.
3Reliability
If flag-lock mechanisms and burst refresh modifications are used, then row hammer refresh can be performed, but detection efficiency is reduced
Solution Approach 1:
The patent applies preliminary action by capturing row hammer addresses in advance during each phase of the refresh interval, before the actual refresh operation is executed. This preliminary capture ensures that multiple addresses are identified and ready for refresh, improving detection efficiency while maintaining the reliability of the refresh capability through systematic preparation in each phase.
Data Source
AI summary
A method of operating a memory device may include receiving, during each phase of a row hammer refresh (RHR) interval, at least one row hammer address (RHA) of a content addressable memory (CAM). The method may further include storing, during each phase of the RHR interval, a received RHA of the at least one received RHA in an address register. Moreover, the method may include refreshing each stored RHA of the CAM via a RHR during the RHR interval. Semiconductor devices and an electronic system are also described.