Arithmetic Circuit With Low Off-State Transistors for Data Retention

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Solution Overview

Problem

Conventional arithmetic circuits face high power consumption and large circuit area due to the need for separate nonvolatile storage and volatile storage means, leading to inefficiencies in data retention and processing.

Innovation Solution

An arithmetic circuit is designed with field-effect transistors having low off-state current, allowing data to be stored by controlling the potential of output signals using transistors that maintain data without the need for additional storage capacitors, thereby reducing power consumption and circuit size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate nonvolatile storage circuit is used to save data, then data retention reliability is improved, but power consumption increases

Engineering Contradiction:

Improvedata retention reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent merges the storage function directly into the arithmetic circuit by using the arithmetic circuit's own nodes to hold data. The arithmetic circuit includes nodes that can maintain data states without requiring separate storage elements, thereby combining computation and storage functions in a single integrated structure that reduces power consumption while maintaining data retention reliability.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If separate nonvolatile storage circuit is used to save data, then data retention reliability is improved, but circuit area increases

Engineering Contradiction:

Improvedata retention reliabilityVSAvoidcircuit area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the storage function directly into the arithmetic circuit by using the arithmetic circuit's own nodes to hold data. The arithmetic circuit includes nodes that can maintain data states without requiring separate storage elements, thereby combining computation and storage functions in a single integrated structure that reduces circuit area while maintaining data retention reliability.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If conventional storage means is used, then data can be stored, but number of elements increases

Engineering Contradiction:

Improvedata storage capabilityVSAvoidnumber of elements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the storage function directly into the arithmetic circuit by using the arithmetic circuit's own nodes to hold data. The arithmetic circuit includes nodes that can maintain data states without requiring separate storage elements, thereby combining computation and storage functions in a single integrated structure that reduces the number of elements while maintaining data storage capability.

Inventive Principle:

Principle #5Merging (Combining)

4Ease of operation

If data is transferred through data bus between arithmetic circuit and storage circuit, then data can be transferred, but power consumption increases

Engineering Contradiction:

Improvedata transfer capabilityVSAvoidpower consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent extracts the storage function from separate storage circuits and integrates it directly into the arithmetic circuit structure. By using the arithmetic circuit's internal nodes to hold data, the need for data transfer through external data buses is eliminated, thereby reducing power consumption while maintaining data transfer capability within the integrated circuit.

Inventive Principle:

Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables efficient data retention with reduced power consumption and smaller circuit area, eliminating the need for separate storage means and enhancing operation speed.

Implementation Method 1

a field-effect transistor with low off-state current is used as each of the first and second transistors

Methodology Applied

Scientific EffectField-effect transistor operation: Electric Field

Implementation Method 2

an off-state current per micrometer of channel width of each of the first and second field-effect transistors is lower than or equal to 10 aA

Methodology Applied

Scientific EffectOff-state current suppression: Electrical Resistance

Data Source

PatentUS10090333B2Arithmetic circuit and method of driving the same

Publication Date: 2018.10.02 SEMICON ENERGY LAB CO LTD

AI summary

In order to reduce power consumption, an arithmetic circuit having a function of performing a logic operation processing based on an input signal, storing a potential set in accordance with the result of the logic operation processing as stored data, and outputting a signal with a value corresponding to the stored data as an output signal. The arithmetic circuit includes an arithmetic portion performing the logic operation processing, a first field-effect transistor controlling whether a first potential, which is the potential corresponding to the result of the logic operation processing is set, and a second field-effect transistor controlling whether the potential of the output signal data is set at a second potential which is a reference potential.