Memory Redundancy Word Line Activation for Data Integrity
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Solution Overview
Problem
As memory integration increases, the reduced interval between word lines leads to increased coupling effects, causing word line disturbance that can damage data in memory cells, especially those adjacent to frequently activated word lines, before they are refreshed.
Innovation Solution
Incorporating redundancy word lines and a control circuit that activates adjacent word lines in response to an active signal when a word line with a high number of activations is replaced, to prevent data degradation by refreshing memory cells connected to these adjacent word lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the degree of integration of memory is increased, then memory density is improved, but the interval between word lines is reduced leading to increased coupling effect and word line disturbance
Solution Approach 1:
The patent applies preliminary action by activating adjacent word lines before the frequently activated word line causes disturbance to adjacent memory cells. The control circuit detects when a word line has been activated a reference number of times and proactively activates adjacent word lines to perform preliminary refresh operations, preventing data degradation before it occurs.
Solution Approach 2:
The patent implements feedback through the control circuit that monitors the activation count of each word line. When a word line reaches a reference number of activations, the control circuit uses this feedback information to trigger activation of adjacent word lines, creating a closed-loop system that dynamically responds to usage patterns to prevent word line disturbance.
2Speed
If a word line is frequently activated for data access, then access speed is improved, but data in adjacent memory cells degrades due to increased coupling effect
Solution Approach 1:
The system performs preliminary refresh operations on adjacent memory cells by activating adjacent word lines before disturbance occurs. This preliminary action maintains data integrity in cells that would otherwise be vulnerable to coupling effects from frequently activated word lines.
Solution Approach 2:
The control circuit acts as an intermediary between the frequently activated word line and the adjacent memory cells. It detects the high activation count and mediates by activating adjacent word lines to perform refresh operations, thereby protecting adjacent cells from the harmful coupling effects while allowing the frequently activated word line to continue its high-speed operations.
3Reliability
If redundancy word lines are added to replace frequently activated word lines, then data reliability is improved, but device complexity increases
Solution Approach 1:
The patent uses redundancy word lines as copies of the frequently activated word lines. Instead of modifying the original word line structure, the system creates duplicate word lines that can be activated to replace the frequently activated ones, thereby maintaining reliability without fundamentally changing the existing architecture.
Solution Approach 2:
The system dynamically selects which word lines to activate based on real-time usage patterns. The control circuit monitors activation counts and dynamically decides whether to use the original word line or switch to a redundancy word line, providing flexibility without requiring static reconfiguration of the memory architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively prevents data degradation due to word line disturbance by actively managing and refreshing memory cells connected to frequently activated word lines, ensuring data integrity even when word lines with high activation rates are replaced by redundancy lines.
Implementation Method 1
as the coupling effect between adjacent word lines increases as described above, a phenomenon occurs, in which a data of a memory cell connected to a word line adjacent to a frequently activated word line is damaged
Data Source
AI summary
A memory includes first to Nth word lines, first to Mth redundancy word lines configured to replace M number of word lines among the first to Nth word lines, and a control circuit configured to activate at least one adjacent word line adjacent to a Kth redundancy word line (1≦K≦M) in response to an active signal, in the case where a word line corresponding to an inputted address among the first to Nth word lines is replaced with the Kth redundancy word line among the first to Mth redundancy word lines in a first mode.