Host-to-Flash Address Mapping Table Update via RAM Buffering
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Solution Overview
Problem
The existing methods for updating host-to-flash address mapping tables in flash memory devices are inefficient, leading to performance delays and potential timeouts during host write commands due to the need to update multiple H2F sub-tables.
Innovation Solution
The method involves allocating space in RAM for a first H2F sub-table and intermediate information, updating these during host write or discard commands, and then programming the updated sub-tables into the flash module, allowing for efficient updating of the H2F table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the H2F table is updated by programming multiple H2F sub-tables into the flash module during host write commands, then the address mapping is maintained, but the system performance deteriorates due to time-consuming sequential programming operations
Solution Approach 1:
The patent pre-allocates RAM space for H2F sub-tables and intermediate information before host write commands arrive. During command execution, updates are performed in RAM rather than directly in flash memory, preparing the data structure in advance for efficient batch programming.
Solution Approach 2:
The patent introduces RAM as an intermediary buffer between the host controller and flash memory. The H2F sub-tables are first updated in RAM during host write commands, then programmed to flash memory in a separate batch operation, decoupling the update process from the command execution time.
2Reliability
If multiple H2F sub-tables are programmed sequentially into the flash module, then the complete address mapping is updated, but the update time increases causing timeouts
Solution Approach 1:
The patent merges multiple individual H2F sub-table programming operations into a single batch programming operation. Instead of programming each sub-table separately during host write commands, all updated sub-tables are accumulated in RAM and programmed together in one operation, significantly reducing total update time.
Solution Approach 2:
The system performs preliminary updates to H2F sub-tables in RAM during host write commands without immediately programming them to flash memory. This allows multiple sub-tables to be prepared in advance and programmed in a single batch operation, reducing the critical path time for address mapping updates.
3Reliability
If H2F sub-tables are updated directly in the flash module during host write commands, then the mapping is current, but the processing overhead increases
Solution Approach 1:
The patent uses RAM as an intermediary working space between the host controller and flash memory. H2F sub-table updates are performed in RAM during host write commands, leveraging RAM's fast random access capabilities to reduce processing overhead compared to direct flash memory updates.
Solution Approach 2:
The patent segments the H2F table into multiple sub-tables that can be independently updated in RAM. This segmentation allows parallel processing of different sub-tables during host write commands, reducing the processing overhead compared to updating a single large table sequentially in flash memory.
Data Source
AI summary
The invention relates to a method, a non-transitory computer-readable program product and an apparatus for updating a host-to-flash address mapping (H2F) table. The method includes: allocating space in a random access memory (RAM) for a first H2F sub-table and intermediate information, which is used to update a second H2F sub-table in a flash module; updating the first H2F sub-table and the intermediate information temporarily stored in the RAM during an execution of a host write command or a host discard command; and in a table update procedure, programming the first H2F sub-table temporarily stored in the RAM into a system block in the flash module, updating the second H2F sub-table according to the intermediate information stored in the RAM, and programming updated second H2F sub-table into the system block in the flash module.