NAND Initialization Data Block Dummy Pattern for Lower Read Loading
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Solution Overview
Problem
Existing flash memory devices experience increased power consumption and peak current due to unnecessary channel charge filling in NAND cell strings during initialization data block access, leading to elevated word line loading.
Innovation Solution
Implementing a dummy pattern in unused memory cells of the initialization data block to keep them turned off during read operations, thereby preventing channel connection to the common source line and reducing word line loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If initialization data is stored in all NAND cell strings, then data storage capacity is maximized, but peak current and power consumption increase due to unnecessary channel charge filling
Solution Approach 1:
The patent applies local quality by programming dummy patterns only in specific unused memory cells of certain NAND cell strings (second cell strings) while leaving other cells (first cell strings) with initialization data unprogrammed or differently programmed. This creates localized differences in cell states within the same initialization data block, allowing unused cells to be turned off during read operations without affecting the storage capacity of cells containing actual initialization data.
2Reliability
If all NAND cell strings are accessed during initialization data read operations, then complete data retrieval is ensured, but word line loading increases due to activated channels
Solution Approach 1:
The patent implements preliminary action by pre-programming dummy patterns into unused memory cells of the second NAND cell strings before initialization data read operations. This preliminary programming ensures that when read operations are performed, these pre-programmed cells can be reliably turned off by applying read voltages, preventing unnecessary channel activation and reducing word line loading during the actual data retrieval process.
3Use of energy by moving object
If dummy patterns are programmed in all unused memory cells, then peak current is reduced by keeping cell strings turned off, but manufacturing complexity increases
Solution Approach 1:
The patent applies partial action by programming dummy patterns only in the unused memory cells of the second NAND cell strings rather than in all unused cells across all cell strings. This selective approach reduces peak current during read operations by turning off specific cell strings while minimizing the manufacturing complexity associated with programming dummy patterns throughout the entire memory array.
Data Source
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AI summary
A method of setting an initialization data block (ID_BLK) of a non-volatile memory device includes generating initialization data and a dummy pattern to be programmed into the initialization data block (ID _BLK), programming the initialization data for initializing the nonvolatile memory device into memory cells of first NAND cell strings (NS1-NS3) corresponding to an initialization data area of the initialization data block (ID _BLK), and programming the dummy pattern in memory cells of second NAND cell strings (NS11-NS13, NS21-NS23, NS31-NS33) corresponding to unused areas of the initialization data block (ID _BLK), wherein the memory cell programmed with the dummy pattern is turned off by a read voltage provided to the initialization data block (ID _BLK).