Dual-Precision Analog Memory Cell for Neural Network Weight Storage

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Solution Overview

Problem

Current analog nonvolatile memory elements suffer from limited precision, accuracy degradation due to dynamic range limitations, and are unsuitable for neural network applications due to asymmetric and nonlinear weight updates.

Innovation Solution

The implementation of dual-precision analog memory cells, comprising a high precision volatile memory element coupled with a low precision nonvolatile memory element, allowing for seamless transition between training and inference phases in neural networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If analog nonvolatile memory elements are used, then power consumption is reduced and storage duration is extended, but precision and accuracy degrade due to limited dynamic range

Engineering Contradiction:
Improvepower consumptionVSAvoidprecision
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The memory system is segmented into two distinct components: a volatile memory element for high-precision weight storage during training, and a non-volatile memory element for low-power storage during inference. This segmentation allows each component to operate in its optimal regime, resolving the contradiction between precision and power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between volatile and non-volatile memory elements based on operational phase. During training, the volatile element provides high precision; during inference, the non-volatile element provides low power consumption. This dynamic switching resolves the contradiction by making the system adaptable to different operational requirements.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If analog nonvolatile memory elements are used, then power consumption is reduced, but weight updates become asymmetric and nonlinear

Engineering Contradiction:
Improvepower consumptionVSAvoidweight update accuracy
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The weight update function is segmented into two phases: training phase using volatile memory for precise, symmetric weight updates, and inference phase using non-volatile memory for power-efficient operation. This segmentation ensures that asymmetric and nonlinear weight update issues are confined to the training phase only.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The volatile memory element acts as a temporary, disposable working memory for training operations where precise weight updates are critical. After training, its contents are transferred to the non-volatile memory, and the volatile memory is reset. This approach accepts the high power consumption of volatile memory during training as a necessary investment for achieving accurate weight updates.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If single-precision memory elements are used, then device complexity is reduced, but accuracy degrades for neural network applications

Engineering Contradiction:
Improvedevice complexityVSAvoidaccuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The memory system is segmented into dual-precision components that work together: the volatile memory element provides high precision for training accuracy, while the non-volatile memory element provides durability for inference. This segmentation achieves high accuracy without requiring a single overly complex high-precision non-volatile memory element.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses a composite memory architecture combining volatile and non-volatile memory elements, each with complementary strengths. This composite approach achieves high accuracy and reliability that neither component could provide alone, resolving the contradiction between device complexity and accuracy.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS20250166686A1Dual-precision analog memory cell and array
Publication Date: 2025.05.22 HEFEI RELIANCE MEMORY LTD
  • US20250166686A1 patent drawing
  • US20250166686A1 patent drawing
  • US20250166686A1 patent drawing

AI summary

Dual-precision analog memory cells and arrays are provided. In some embodiments, a memory cell, comprises a non-volatile memory element having an input terminal and at least one output terminal; and a volatile memory element having a plurality of input terminals and an output terminal, wherein the output terminal of the volatile memory element is coupled to the input terminal of the non-volatile memory element, and wherein the volatile memory element comprises: a first transistor coupled between a first supply and a common node, and a second transistor coupled between a second supply and the common node; wherein the common node is coupled to the output terminal of the volatile memory element; and wherein gates of the first and second transistors are coupled to respective ones of the plurality of input terminals of the volatile memory element.