Memory Card BIST Firmware for Efficient Self-Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large-capacity memory cards, such as moviNAND, require extensive testing due to high integration density, leading to increased test time and equipment costs, and existing built-in self-test (BIST) methods are not efficient for these cards without modifying their internal design.
Innovation Solution
A memory card with embedded BIST firmware that allows self-testing even when disconnected from an external device, using a controller and power supply to perform defect tests and transmit results, reducing the need for continuous external connection and minimizing test equipment investment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional testing methods are used for large-capacity memory cards, then comprehensive testing can be performed, but testing time and equipment costs increase significantly
Solution Approach 1:
The memory card performs self-testing using a built-in BIST circuit that generates test patterns and evaluates memory cell responses autonomously. The test pattern generator creates sequences of test data that are written to and read from memory cells, with the results evaluated by a comparator without requiring external testing equipment.
Solution Approach 2:
The BIST circuit is extracted as a separate functional module within the memory card, including a test pattern generator, memory cell array, and comparator. This extracted circuit can operate independently to perform comprehensive testing of the memory cells without requiring external testing devices.
2Adaptability or versatility
If BIST circuit is added to memory card, then self-testing capability is provided, but device complexity increases
Solution Approach 1:
The BIST circuit components (test pattern generator, comparator, control logic) are merged into a single integrated circuit that works together with the memory cell array. The test pattern generator is configured to generate test patterns that are directly applied to the memory cells, and the comparator immediately evaluates the results, creating a unified testing system.
Solution Approach 2:
The BIST circuit is designed to test all memory cells across the entire memory card, making it universally applicable to different memory cell configurations and capacities. The same BIST circuit can accommodate various memory sizes and layouts without requiring redesign, providing multi-functional testing capability.
3Measurement precision
If external testing equipment is used, then detailed defect analysis is possible, but test equipment investment costs increase
Solution Approach 1:
The memory card includes a self-contained BIST circuit that performs defect detection autonomously without requiring external testing equipment. The test pattern generator creates test sequences, the memory cells process the tests, and the comparator evaluates results all within the card itself, eliminating the need for expensive external testing devices.
Solution Approach 2:
The defect testing functionality is extracted from external equipment and embedded directly into the memory card as an integrated BIST circuit. This extraction eliminates the need for separate testing equipment investment while maintaining the ability to perform detailed defect analysis on all memory cells.
Data Source
AI summary
A memory card includes a memory cell, a connector, a controller, and firmware. The memory cell can switch between a plurality of states. The connector can be connected to an external device and exchange signals including commands and data with the external device. The controller exchanges signals with the connector, analyzes a received signal, and accesses the memory cell to record, retrieve or modify data based on the analysis result. The firmware is located within the controller, controls the operation of the controller, and can be set to a test mode or a user mode. When the firmware receives a test command from the external device and the firmware is set to the test mode, the firmware performs a defect test on the memory cell and transmits the result of the defect test to the external device through the connector.