Fast Bit Error Rate Estimation in Nonvolatile Memory
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonvolatile memory systems face challenges in efficiently detecting and correcting bit errors, which can require significant time and resources, especially when using Error Correction Codes (ECC).
Innovation Solution
The method involves rapidly estimating the Bit Error Rate (BER) by recording and comparing the distribution of data states during storage and read operations, allowing for appropriate data handling schemes to be selected, such as on-chip copying or ECC correction, based on calculated error rates, and using test data to extrapolate error rates for user data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Error Correction Codes (ECC) are used to detect and correct bit errors in nonvolatile memory, then data reliability is improved, but processing time and resource consumption increase significantly
Solution Approach 1:
The patent applies partial action by implementing a two-stage error handling approach: first performing a fast BER estimation on a sample or subset of data to determine the error rate, and only then applying full ECC correction when necessary. This avoids the excessive time consumption of ECC on all data while maintaining reliability when errors are present.
Solution Approach 2:
The patent introduces BER estimation as an intermediary step between data reading and ECC correction. This intermediary mechanism quickly assesses error rates and acts as a gatekeeper, determining whether full ECC processing is needed, thereby reducing overall processing time while maintaining data reliability.
2Reliability
If Error Correction Codes (ECC) are applied to all data reads, then data reliability is improved, but resource utilization increases significantly
Solution Approach 1:
The patent implements partial action by applying ECC only to data that exhibits error patterns above a certain threshold. The BER estimation mechanism identifies which data portions actually need correction, avoiding the waste of computational resources on error-free data while ensuring reliability for problematic data.
Solution Approach 2:
The patent uses feedback from BER estimation results to dynamically control ECC application. The system continuously monitors error rates and adjusts ECC processing accordingly, applying correction resources only when the feedback indicates errors are present, thereby optimizing resource utilization while maintaining reliability.
3Speed
If fast BER estimation is performed by comparing data distribution shapes, then processing speed is improved, but measurement precision may be reduced compared to full ECC analysis
Solution Approach 1:
The patent applies preliminary action by performing BER estimation through data distribution shape comparison before committing to full ECC processing. This preliminary assessment provides a quick indication of error rates that is sufficiently precise for decision-making, enabling fast triage while maintaining adequate measurement precision for determining whether further correction is needed.
Data Source
AI summary
Changes in the distribution of memory cells across memory states allow calculation of Bit Error Rate (BER). Comparison of test data stored in memory and a known good copy of the test data provides test data BER from which user data BER may be obtained. Data may be handled differently according to its BER.