Data Shaping for Integrated Memory Assembly Wear Reduction

Solution Overview

Problem

The challenge in non-volatile semiconductor memory devices is to balance error correction for data integrity with the need to reduce wear on memory cells, as adding more error correction information slows down programming and increases power consumption.

Innovation Solution

Performing data shaping and adding error correction information at the memory die rather than the memory controller, allowing for increased error correction without the performance and power penalties, by encoding and storing codewords directly on the memory die.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If more error correction information is added to user data, then error correction capability is improved, but programming time increases and power consumption increases

Engineering Contradiction:

Improveerror correction capabilityVSAvoidprogramming speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

Data shaping is performed in advance before error correction coding, transforming the input data to have a non-uniform distribution that reduces memory wear. This preliminary transformation allows the system to use more error correction bits without proportionally increasing programming time, because the shaping operation is efficient and enables better utilization of the additional error correction information.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the distribution parameter of the data by applying data shaping transformations that convert uniformly distributed input data into non-uniformly distributed shaped data. This parameter change reduces the frequency of writing to extreme states (0 and 1), thereby reducing memory wear while allowing increased error correction capability without linearly increasing programming time and power consumption.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If more error correction information is added to user data, then error correction capability is improved, but power consumption increases

Engineering Contradiction:

Improveerror correction capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

Data shaping is performed in advance before error correction coding, transforming the input data to have a non-uniform distribution that reduces memory wear. This preliminary transformation allows the system to use more error correction bits without proportionally increasing programming time, because the shaping operation is efficient and enables better utilization of the additional error correction information.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the distribution parameter of the data by applying data shaping transformations that convert uniformly distributed input data into non-uniformly distributed shaped data. This parameter change reduces the frequency of writing to extreme states (0 and 1), thereby reducing memory wear while allowing increased error correction capability without linearly increasing programming time and power consumption.

Inventive Principle:

Principle #35Parameter changes

3Duration of action of stationary object

If data shaping is performed to reduce memory wear, then endurance is improved, but data distribution uniformity changes

Engineering Contradiction:

Improvememory enduranceVSAvoiddata distribution uniformity

Core Design Contradiction:

Duration of action of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent intentionally changes the distribution parameter of the data by applying data shaping transformations that convert uniformly distributed input data into non-uniformly distributed shaped data. This parameter change is beneficial because it reduces the frequency of writing to extreme states (0 and 1), thereby reducing memory wear and improving endurance, while the transformation is reversible during read operations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Data shaping acts as an intermediary transformation between the original user data and the stored data. The shaping process transforms the data distribution to reduce wear, and the inverse shaping process during read operations restores the original uniform distribution, allowing the system to benefit from non-uniform distribution during writing while maintaining data integrity and uniformity during reading.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11301321B2Data shaping for integrated memory assembly

Publication Date: 2022.04.12 SANDISK TECHNOLOGIES LLC

AI summary

A non-volatile memory system comprises an integrated memory assembly in communication with a memory controller. The integrated memory assembly comprises a memory die bonded to a control die with bond pads. The control die includes one or more control circuits for controlling the operation of the memory die. The one or more control circuits are configured to receive data to be programmed into the memory die, select a number of parity bits, encode the data to add error correction information and form a codeword that includes the number of parity bits, shape the codeword, and program the shaped codeword into the memory die.