Flash Memory Controller Multi-Block Erase Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flash memory systems face inefficiencies due to the inability to perform sequential erasure of data at the page level and the limitation of in-place updates, leading to invalid pages that require costly recycling processes.
Innovation Solution
A method for controlling flash memory that supports a multi-block erase function, allowing simultaneous erasure of data across multiple blocks, and calculates the cost of different block recycling schemes to select the most optimized approach, enabling selective erasure and management of invalid pages at the page level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If data is updated in place in flash memory pages, then update operations are simple, but flash memory does not support in-place updates requiring data to be moved to different pages
Solution Approach 1:
The patent introduces a buffer memory as an intermediary between the host and flash memory. The buffer temporarily stores data during update operations, allowing the system to perform logical in-place updates by coordinating reads from old pages, writes to new pages, and management of valid/invalid page states, even though the physical flash memory cannot overwrite existing data
2Device complexity
If erasure is performed at block level, then flash memory architecture is simple, but page-level selective erasure is required for efficient recycling
Solution Approach 1:
The patent segments the block erasure operation into page-level operations by introducing granular invalid page management. The flash memory controller identifies and manages individual invalid pages within blocks, allowing selective recycling of only the necessary pages rather than erasing entire blocks, thereby improving recycling efficiency while maintaining the underlying block architecture
3Loss of energy
If multiple blocks are erased simultaneously, then block recycling cost is reduced, but multi-block erase function must be supported
Solution Approach 1:
The patent merges multiple block erasure operations into a single simultaneous operation. The flash memory controller identifies multiple blocks containing invalid pages and erases them concurrently in one operation, reducing the total number of erasure cycles required and lowering the overall recycling cost, while requiring the flash memory to support multi-block erase functionality
Data Source
AI summary
Disclosed is a flash memory controlling method and controlling device. The flash memory controlling method including calculating a cost for each of available block recycling schemes based on a multi-block erase function when the multi-block erase function is supported, the multi-block erase function being a function that simultaneously erases data stored in a plurality of blocks of a flash memory and selecting at least one scheme from among the available block recycling schemes based on the calculated cost, and managing at least one block using the at least one method selected from among the available block recycling schemes.