AWLSB Management for Memory Block Read Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional memory sub-systems face issues with race conditions and unreliable data retrieval due to improper handling of automatic wordline status bypass (AWLSB) functions in prioritized queues, especially when read operations are executed on partially programmed blocks before the AWLSB function is disabled.
Innovation Solution
The implementation of a system and method for managing AWLSB functions ensures that read commands follow program commands in execution sequences by removing existing AWLSB entries when the last page of a block is fully programmed, thereby maintaining a proper command execution order and preventing race conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If read operations are executed on partially programmed blocks before AWLSB function is disabled, then read speed is improved, but data reliability deteriorates due to race conditions
Solution Approach 1:
The system disables the AWLSB function in advance before executing read operations on partially programmed blocks. By removing AWLSB entries from the active function list before the read command is issued, the system prevents race conditions from occurring, ensuring data reliability while still allowing fast read access.
2Loss of time
If AWLSB function is enabled for all open blocks, then read sensing time is improved, but device complexity increases due to management overhead
Solution Approach 1:
Instead of uniformly enabling AWLSB for all open blocks, the system selectively enables AWLSB only for specific blocks that require it based on their programming status. The system maintains a list of blocks with AWLSB enabled and checks this list before each read operation, applying the bypass function locally where needed rather than globally, thus reducing unnecessary management overhead.
Solution Approach 2:
The AWLSB function list is dynamically updated as blocks transition between partially programmed and fully programmed states. The system automatically adds blocks to the AWLSB enabled list when they become partially programmed and removes them when fully programmed, allowing the system to adapt to changing block states without manual intervention or complex static management.
3Manufacturing precision
If program commands are prioritized over read commands, then manufacturing precision is improved, but productivity decreases due to command execution delays
Solution Approach 1:
The AWLSB function acts as an intermediary mechanism that allows read commands to execute correctly on partially programmed blocks without requiring them to wait for program commands to complete. By enabling the bypass function for specific blocks, the system mediates between the need for program precision and read throughput, allowing both operations to proceed efficiently without mutual blocking.
Data Source
AI summary
A processing device access a command to program data to a page in a block of a memory device. The processing device determines whether the page is a last remaining open page in the block. The processing device accesses a list that indicates enablement of a function to apply read level offsets to one or more open blocks in the memory device. The processing device determines the list includes an entry that matches to the block. The entry indicates enablement of the function to apply read level offsets to the block. The processing device disables the function based on determining the page is a last remaining open page in the block. The processing device adds the command to a prioritized queue of commands. The memory device executes commands from the prioritized queue in an order based on a priority level assigned to each command.