LDPC Codeword Distribution Across Memory Dies to Lower RBER
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In solid-state memory devices, error correction codes like LDPC codewords are typically stored in a single memory die, leading to high raw bit error rates (RBER) when decoding, as the decoder must mitigate errors across all pages of NAND dies, which can result in inefficient error correction.
Innovation Solution
A codeword distribution manager is implemented to divide the codeword into portions and distribute them across multiple individual storage units, each with varying RBERs, allowing for parallel reads and averaging the RBER, thereby reducing the overall error correction burden.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LDPC codeword is completely stored in a single memory die, then the storage structure is simple, but the raw bit error rate (RBER) is high because the decoder must mitigate the worst RBER of all pages across all NAND dies
Solution Approach 1:
The patent divides the LDPC codeword into multiple segments and distributes them across different memory dies or pages. Specifically, the codeword is split such that different portions are stored in different physical locations, allowing the decoder to benefit from the average RBER across multiple storage units rather than the worst-case RBER of a single unit. This segmentation directly resolves the contradiction by improving reliability through distribution while managing complexity through organized partitioning.
2Reliability
If the codeword is stored across multiple individual storage units, then the raw bit error rate is reduced by averaging RBERs, but the storage and read operations become more complex
Solution Approach 1:
The patent implements preliminary action by pre-organizing the codeword segments across storage units with associated metadata that tracks the distribution. The memory controller maintains information about which codeword portions are located where, enabling efficient retrieval. This preliminary organization reduces the operational complexity during read operations, as the system already has the mapping information ready rather than needing to search or reconstruct the distribution dynamically.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Embodiments are directed towards apparatuses, methods, and systems for a codeword distribution manager to divide a codeword into portions to be written to individual storage units and read from the corresponding different individual storage units to reduce a raw bit error rate (RBER) related to storage of the codeword. In embodiments, the codeword distribution manager is included in a memory controller and the plurality of individual storage units are coupled to the memory controller and include individual memory die or individual pages of a memory die. In embodiments, the codeword is a single codeword and includes encoded data and an error correction code. In some embodiments, the codeword includes a low density parity data check code (LDPC). Additional embodiments may be described and claimed.