DRAM SR Cycle and AR Number Testing via Data Retention Curves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Customers are unable to determine the SR cycle of DRAMs due to customization by manufacturers, which affects the accuracy of data retention capacity and AR number required for refresh operations, leading to potential data loss from electric leakage.
Innovation Solution
A method and device for testing SR cycle and AR number by executing data-retention-capacity acquisition steps, including sending SR entry and exit commands, detecting current data retention capacity, and determining the SR cycle and AR number through function curves, allowing for accurate measurement and analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If DRAM manufacturers customize SR cycle and AR number according to their own technological level, then manufacturing flexibility is improved, but measurement precision deteriorates because customers cannot determine the actual values
Solution Approach 1:
The memory device performs self-testing by automatically executing SR operations and measuring its own data retention capacity at different refresh times, eliminating the need for external specialized testing equipment and allowing manufacturers to verify their customized parameters
Solution Approach 2:
The testing method uses periodic SR operations with varying refresh times to systematically probe the memory's data retention characteristics, allowing the determination of SR cycle through analyzing the periodic pattern of data retention capacity changes
2Device complexity
If inaccurate SR cycle and AR number values are used, then device complexity is reduced, but reliability deteriorates due to potential data loss from electric leakage
Solution Approach 1:
The testing method implements feedback by measuring data retention capacity at different refresh times and using this information to accurately determine the SR cycle and optimal AR number, ensuring reliable data retention parameters are established
Solution Approach 2:
The method performs preliminary testing to determine accurate SR cycle and AR number values before actual DRAM operation, preventing data loss by establishing correct refresh parameters in advance
3Difficulty of detecting and measuring
If traditional current-based SR cycle measurement methods are used, then measurement capability is improved, but accuracy deteriorates due to overlapped cycles that cannot be distinguished
Solution Approach 1:
The method replaces current-based measurement with data retention capacity-based measurement, substituting electrical current detection with logical data state verification, which avoids the overlapped cycle problem by using discrete read operations to detect refresh completion
Solution Approach 2:
The testing method uses data state changes (from retained to lost) as indicators of SR cycle completion, analogous to using visual color changes to distinguish periodic events, allowing clear identification of refresh cycle boundaries
Data Source
AI summary
The present disclosure relates to the field of integrated circuit technologies, and provides a method and device for testing an SR cycle as well as a method and device for testing an AR number. The method for testing an SR cycle includes: executing a preset number of data-retention-capacity acquisition steps, the data-retention-capacity acquisition step including determining a preset refresh time; sending an SR entry command to control a memory to enter an SR operation; sending an SR exit command to control the memory to exit the SR operation after the memory executes the SR for the preset refresh time; detecting a current data retention capacity of the memory; obtaining a cycle of a function of the data retention capacity with respect to the corresponding preset refresh time; and determining the SR cycle of the memory with the cycle of the function.