Wordline Group Sensing Parameters for Memory Read Window Variability
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Solution Overview
Problem
Memory devices exhibit varying read window budgets (RWB) across different wordlines, leading to inconsistent memory device reliability due to manufacturing variability, which affects programming and read times.
Innovation Solution
Implementing adaptive time sense parameters and overdrive voltage parameters for specific groups of wordlines, particularly those with lower RWBs, to optimize memory access operations, using configuration tables to determine unique parameters for each group.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uniform time sense parameters and overdrive voltage parameters are used for all wordlines, then device complexity is reduced and ease of operation is improved, but memory device reliability deteriorates due to manufacturing variability across different wordlines
Solution Approach 1:
The patent divides the wordline set into multiple groups (e.g., first group, second group, third group) based on their read window budget characteristics. Each group is assigned distinct time sense parameters and overdrive voltage parameters from configuration tables, allowing differentiated optimization for each segment while maintaining manageable complexity through systematic grouping.
Solution Approach 2:
The patent applies the principle of local quality by assigning specific parameter sets tailored to each wordline group's characteristics. For example, wordlines with lower RWBs receive different parameter configurations than those with higher RWBs, optimizing performance locally for each group rather than applying a uniform configuration globally.
2Reliability
If adaptive time sense parameters and overdrive voltage parameters are implemented for specific wordline groups, then memory device reliability is improved, but device complexity increases due to multiple parameter configurations
Solution Approach 1:
The patent segments wordlines into groups based on RWB characteristics and implements adaptive parameters only for specific groups (e.g., RWB-limiting wordlines). This selective segmentation improves reliability where needed while avoiding unnecessary complexity for wordlines that do not require optimization.
Solution Approach 2:
The patent applies adaptive parameter optimization partially, focusing only on wordline groups that benefit most (e.g., those with lower RWBs). This partial action approach improves overall reliability without implementing full complexity across all wordlines, balancing performance gain with manageable complexity.
3Reliability
If longer time sense parameters are used for wordlines with lower RWBs, then reliability of those wordlines is improved, but average programming and read times increase
Solution Approach 1:
The patent applies different time sense parameters locally to specific wordline groups based on their RWB characteristics. Wordlines with lower RWBs receive longer time sense parameters to ensure reliable reads, while wordlines with higher RWBs use shorter parameters to minimize access time, optimizing the trade-off locally for each group.
Solution Approach 2:
The patent uses longer time sense parameters only partially, applying them selectively to wordline groups that require them (e.g., RWB-limiting wordlines) rather than uniformly to all wordlines. This partial application maintains high reliability for critical wordlines while minimizing the impact on average access time across the entire memory device.
Data Source
AI summary
A system includes a memory device and a processing device, operatively coupled with the memory device, to perform operations including: receiving a request to perform a memory access operation on a set of cells associated with a wordline of the memory device; determining that the wordline is disposed on a first deck of the memory deck; responsive to determining that the wordline is disposed on the first deck, determining that the wordline is associated with a first group of wordlines associated with the first deck; and responsive to determining that the wordline is associated with the first group of wordlines associated with the first deck, performing the memory access operation on the set of cells connected to the wordline using a first time sense parameter, wherein the first time sense parameter corresponds to the first group of wordlines associated with the first deck.