Flash Memory Controller Space Trimming via Mapping Table Postponement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current data storage devices face inefficiencies in space trimming due to the time-consuming process of downloading, modifying, and sealing large sub-tables during flash memory trimming, especially when dealing with huge trimming spaces, which affects performance and resource usage.
Innovation Solution
A data storage device architecture that includes a controller and temporary storage, which programs trimming tags and information flags to postpone the update of the host-to-device mapping table, allowing for partial updates in background, thereby reducing the burden on system resources and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the controller downloads, modifies, and seals large sub-tables during flash memory trimming, then the space trimming can be performed, but the time required for trimming increases significantly
Solution Approach 1:
The controller programs trimming tags and information flags into the non-volatile memory before actually performing the trimming operation. This preliminary action allows the trimming information to be stored and processed later, eliminating the need to immediately download and modify large sub-tables, thus significantly reducing the time required for trimming operations.
Solution Approach 2:
The patent introduces trimming tags and information flags as intermediary elements that mediate between the trimming command and the actual mapping table updates. These intermediaries store trimming information in a compact form and enable partial updates in the background, avoiding the need to process entire large sub-tables immediately.
2Reliability
If the controller updates the host-to-device mapping table completely during trimming, then the trimming is accurate, but the burden on system resources increases
Solution Approach 1:
The patent segments the mapping table update process into partial updates based on trimming information flags. Instead of updating the entire host-to-device mapping table, the controller identifies and updates only the specific portions that correspond to trimmed areas, reducing the burden on system resources while maintaining trimming accuracy.
Solution Approach 2:
The controller performs partial updates of the mapping table rather than complete updates. By using trimming information flags to identify only the necessary portions to update, the system achieves sufficient accuracy for trimming while significantly reducing the resource burden compared to complete table updates.
3Productivity
If the controller processes large trimming spaces immediately, then the trimming can be completed, but the performance impact increases
Solution Approach 1:
The controller performs preliminary actions by programming trimming tags and information flags into the non-volatile memory before processing the actual trimming. This allows the trimming to be completed without immediately processing large trimming spaces at full speed, as the preliminary information storage enables background processing.
Solution Approach 2:
The patent enables continuous useful action by allowing background processing of trimming information. The controller can continue other operations while the trimming process progresses in the background using previously stored trimming information, maintaining productivity without significant performance impact.
Data Source
AI summary
Power recovery for data storage devices with an efficient space trimming technology is shown. A controller scans a non-volatile memory according to a programming order, collects a sequence of trimming information flags, and interprets a sequence of storage information scanned from the non-volatile memory to identify logical addresses and trimming code. Based on the logical addresses, a host-to-device mapping (H2F) table is rebuilt. Based on the trimming code, information of medium-length trimming and information of long-length trimming are recognized from a storage area of the non-volatile memory. According to the trimming information for medium-length trimming, dummy mapping data is programmed to the H2F table. According to the trimming information for long-length trimming, a trimming bitmap (TBM) is rebuilt. Each bit in the TBM marks space trimming of a first length.