2D Circulation Shift Register Convolution for Lower-Power CNN Hardware

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Solution Overview

Problem

The conversion of convolution operations into matrix operations in existing convolutional computation devices leads to increased hardware and data processing requirements, resulting in higher power consumption.

Innovation Solution

A convolutional computation device incorporating a two-dimensional circulation shift register and a multiplier-accumulator that performs multiply-accumulate operations on input data and weight data, without converting the input data for matrix operations, thereby reducing hardware and data processing needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If convolution operations are converted into matrix operations, then the computation can be performed using standard linear algebra methods, but the hardware complexity and data processing requirements increase

Engineering Contradiction:
Improvecomputation implementationVSAvoidhardware complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent segments the input data into non-overlapping blocks and processes each block independently through the circulation shift register. This segmentation avoids the need to handle overlapped data regions, reducing hardware complexity while maintaining computational effectiveness for convolution operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of converting convolution to matrix operations (conventional approach), the patent inverts the approach by directly implementing convolution through the circulation shift register's natural data flow properties. This inversion eliminates the need for complex matrix conversion hardware while achieving the same computational goal.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If data is duplicated to handle overlapped input regions, then complete convolution coverage is achieved, but power consumption increases

Engineering Contradiction:
Improveconvolution coverageVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and processes only the necessary non-overlapping data blocks required for convolution, eliminating the need to duplicate data for overlapped regions. The circulation shift register naturally handles the sliding window effect through its cyclic data flow, reducing power consumption while maintaining complete convolution coverage.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The circulation shift register maintains continuous data flow through cyclic shifting, allowing the same hardware to continuously process different data blocks without duplication. This continuous action ensures complete convolution coverage across all regions while avoiding the energy cost of data duplication.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If more data is processed to ensure complete convolution coverage, then accuracy is improved, but data processing time increases

Engineering Contradiction:
Improveconvolution accuracyVSAvoiddata processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary organization of input data into non-overlapping blocks before convolution processing. The circulation shift register is pre-configured to cycle through these blocks systematically, ensuring complete coverage without redundant processing. This preliminary organization maintains accuracy while minimizing processing time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The circulation shift register employs periodic cyclic shifting to systematically process each data block in sequence. This periodic action ensures that all necessary regions are covered for complete convolution accuracy, while the regular rhythm of cyclic shifts optimizes processing efficiency and reduces overall data processing time.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS12625675B2Convolutional computation device
Publication Date: 2026.05.12 DENSO CORP
  • US12625675B2 patent drawing
  • US12625675B2 patent drawing
  • US12625675B2 patent drawing

AI summary

A convolutional computation device includes a two-dimensional circulation shift register unit and one or more multiplier-accumulators. The two-dimensional circulation shift register has storage elements, cyclically shifts the data among the storage elements, provides one or more input window in a predetermined area, and selects the data stored in one of the storage elements disposed in the input window as input data. The one or more multiplier-accumulators generate output data by performing a multiply-accumulate operation on the input data input from the two-dimensional circulation shift register unit and weight data from a predetermined filter.