Card Reader Logic Block Length Inspection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Computer hosts may inadvertently damage data on memory cards due to unsupported logical block lengths, leading to data loss when attempting to write files organized in specific block sizes.

Innovation Solution

A card reader processing unit inspects the logical block length of inserted memory cards and responds with sense data to advise the host not to perform writes if the block length is not supported, using commands like REQUEST SENSE and Read Capacity to determine compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the card reader allows the host to access memory cards with various logical block lengths, then the adaptability of the card reader is improved, but the risk of data damage increases when the host does not support particular block lengths

Engineering Contradiction:

Improvecard reader compatibilityVSAvoiddata damage risk

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The card reader performs preliminary detection of the memory card's logical block length during the REQUEST SENSE command phase, before any write operations are initiated. This advance knowledge allows the card reader to prevent incompatible write operations by setting appropriate sense data flags, thereby avoiding data damage while maintaining broad card compatibility

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The card reader uses the sense data mechanism to provide feedback to the host about the memory card's logical block length capabilities. When the host sends a REQUEST SENSE command, the card reader analyzes the card's block length and returns appropriate sense data that informs the host whether write operations are safe, creating a feedback loop that prevents harmful operations

Inventive Principle:

Principle #23Feedback

2Reliability

If the card reader performs detailed inspection of logical block length, then data integrity is improved, but the operation complexity increases

Engineering Contradiction:

Improvedata integrityVSAvoidinspection process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The card reader leverages existing standard commands (REQUEST SENSE and Read Capacity) that are already part of the memory card interface protocol. By repurposing these existing commands for dual purposes (standard communication and logical block length detection), the system achieves reliable data integrity checking without adding complex custom inspection procedures or additional hardware components

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10489335B1Apparatus and method and computer program product for accessing a memory card

Publication Date: 2019.11.26 SILICON MOTION INC

AI summary

The invention introduces an apparatus for accessing a memory card to at least include a host interface and a processing unit. The processing unit is arranged to operably inspect whether a logical block length utilized in a memory card inserted into a card reader can be supported by a host; and reply to the host with sense data that advises the host not to perform a subsequent write into the memory card through the host interface in response to a request sense command when the logical block length utilized in the memory card cannot be supported by the host.