Memory Device Error Handling via Spare Cell Replacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor memory devices face reliability and lifespan issues due to defective or damaged memory cells, which existing technologies struggle to effectively address.
Innovation Solution
A method and memory device that differentiate memory cells with data errors in real-time by storing address information in a preset memory space and replacing invalid cells with spare cells, ensuring accurate read and write operations and preventing data errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If memory cells are used without error detection and replacement mechanisms, then device complexity is low, but reliability deteriorates due to defective or damaged memory cells
Solution Approach 1:
The patent applies preliminary action by pre-allocating spare memory cells and preset memory spaces before errors occur. The system proactively prepares replacement resources and error detection mechanisms in advance, so when a memory cell becomes defective, the replacement can occur immediately without system downtime or complex runtime decision-making. This resolves the contradiction by establishing reliability through advance preparation while keeping the operational complexity low.
Solution Approach 2:
The patent introduces intermediary components including a preset memory space for storing address information and a comparison unit that mediates between the memory cell and spare memory cell. This intermediary layer handles the complexity of error detection and replacement, allowing the main memory system to operate simply while the intermediary manages the reliability-enhancing functions. The comparison unit acts as a mediator that automatically determines whether to use the original memory cell or switch to the spare cell based on error detection results.
2Reliability
If error detection and spare memory cell replacement mechanisms are implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by implementing error detection and replacement mechanisms only where needed - specifically in the preset memory space and comparison unit - rather than throughout the entire memory system. The majority of the memory system continues to operate with simple, high-speed access, while only the critical path involving defective cells undergoes the more complex error detection and replacement process. This localized approach improves reliability without proportionally increasing overall device complexity.
3Measurement precision
If address information is stored in preset memory space for error-prone cells, then data accuracy is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies copying by creating a duplicate record of the address information for defective memory cells in the preset memory space. Instead of attempting to physically repair or replace the defective cell during manufacturing (which would require high manufacturing precision), the system creates a logical copy - the address information is copied to the preset memory space, allowing the system to bypass the defective cell through software/firmware control. This copying approach achieves data accuracy without imposing stringent manufacturing precision requirements.
Data Source
AI summary
The embodiments provide a method for reading and writing and a memory device. The method includes: applying a read command to the memory device, the read command pointing to address information; reading data to be read out from a memory cell corresponding to the address information pointed to by the read command; and storing the address information pointed to by the read command into a memory bit of a preset memory space if an error occurs in the data to be read out, wherein the preset memory space is provided with a plurality of the memory bits, and each of the plurality of memory bits is associated with a spare memory cell.