Flash Memory Controller Data Dispersion Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flash memory writing speed is hindered by the need to erase entire physical blocks, leading to inefficiencies in processing valid and invalid data, especially when data is not written in the order of logical addresses.
Innovation Solution
A data writing method that configures logical page addresses into logical blocks, records data dispersion degrees, and writes data into flash memory based on these degrees and physical page addresses, ensuring the data dispersion degree of each logical block does not exceed a threshold, thereby optimizing data placement and reducing write time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the entire physical block is erased before writing data, then data can be written into flash memory, but writing speed decreases due to the time-consuming erasure process
Solution Approach 1:
The patent applies preliminary action by pre-erasing physical blocks and maintaining a pool of pre-erased physical blocks before actual data writing occurs. The controller proactively erases physical blocks in advance and stores them in a buffer, so when host write commands arrive, pre-erased blocks are immediately available for writing without waiting for erasure operations. This resolves the contradiction by performing the time-consuming erasure operation beforehand, making the actual writing process faster.
2Ease of operation
If data is written based on host's logical address order, then data management is simple, but data dispersion increases when hosts write in random order
Solution Approach 1:
The patent introduces an intermediary layer (the controller with logical block configuration) between the host and the physical flash memory structure. The controller translates host logical addresses into physical block addresses, allowing the host to write data in any order while the controller reorganizes and consolidates data into physical blocks. This intermediary resolves the contradiction by absorbing the complexity of address translation and data consolidation, enabling both simple host operation and efficient physical data management.
3Adaptability or versatility
If physical blocks are frequently erased and rewritten, then data storage flexibility is maintained, but the number of valid data pages scattered across physical blocks increases
Solution Approach 1:
The patent segments the flash memory into distinct logical blocks that are further divided into physical blocks, with each logical block independently managing its data. This segmentation allows data from a single logical block to be consolidated into fewer physical blocks, reducing the scattering effect. When a logical block needs to be erased or rewritten, only its associated physical blocks are affected, not the entire flash memory. This resolves the contradiction by isolating data management to smaller units, maintaining flexibility while reducing overall data distribution complexity.
Data Source
AI summary
A data writing method for writing data from a host system into a flash memory chip is provided. The method includes configuring a plurality of logical page addresses, grouping the logical page addresses into a plurality of logical blocks, and recording the data dispersion degree of each of the logical blocks. The method also includes receiving write-in data from the host system, identifying a logical block that a logical page address to be written by the host system belongs to, and writing the write-in data into the flash memory chip according to the data dispersion degree of the logical block, wherein the data dispersion degree of each of the logical blocks is not larger than a logical block data dispersion degree threshold value. Accordingly, the method can effectively reduce the time for executing a host write command.