Multi-Dimensional Tensor Mapping Circuit for CPU Load Reduction

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Solution Overview

Problem

Existing neural network processing systems rely heavily on central processing units (CPUs), leading to significant bandwidth consumption and increased power usage due to the extensive computing operations required for machine learning tasks.

Innovation Solution

A tensor access operation circuit is introduced in a neural processor circuit, which indirectly accesses regions of a source tensor in system memory and maps components into an input tensor, allowing for efficient convolution operations through a data processor circuit and neural engine circuit, reducing the load on CPUs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If CPU is used to perform neural network operations, then ease of operation is improved, but use of energy and bandwidth consumption increase

Engineering Contradiction:
Improveease of operationVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

A dedicated neural processing unit (NPU) is introduced as an intermediary between the CPU and system memory. The NPU includes a tensor access operation circuit that indirectly accesses source tensor data from system memory and performs neural network operations locally, reducing the need for CPU intervention and minimizing bandwidth consumption while maintaining ease of operation through hardware acceleration

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If CPU is used to perform neural network operations, then ease of operation is improved, but bandwidth consumption increases

Engineering Contradiction:
Improveease of operationVSAvoidbandwidth consumption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The tensor access operation circuit acts as an intermediary that directly accesses system memory for source tensor data and performs operations locally within the NPU. This eliminates the need for continuous CPU-mediated data transfers, significantly reducing bandwidth consumption while maintaining operational simplicity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The processing system is segmented into distinct functional units: the CPU for control and coordination, the NPU for specialized neural network operations, and system memory for data storage. This segmentation allows the NPU to independently access memory and perform operations without burdening the CPU, reducing overall bandwidth consumption

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If tensor access operation circuit indirectly accesses source tensor, then flexibility in texture transforms is improved, but device complexity increases

Engineering Contradiction:
ImproveflexibilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The tensor access operation circuit serves as an intermediary between system memory and the neural processing units. It indirectly accesses source tensor data and performs rank mapping transformations, providing flexible texture transforms for different neural network configurations while encapsulating the complexity within the dedicated circuit rather than requiring complex CPU software implementations

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS20250252307A1Multi-dimensional tensor support extension in neural network processor
Publication Date: 2025.08.07 APPLE INC
  • US20250252307A1 patent drawing
  • US20250252307A1 patent drawing
  • US20250252307A1 patent drawing

AI summary

Embodiments of the present disclosure relate to a tensor access operation circuit in a neural processor circuit. The neural processor circuit further includes a data processor circuit and at least one neural engine circuit. The tensor access operation circuit indirectly accesses at least a region of a source tensor in a system memory having a rank, and maps one or more source components of the source tensor into an input tensor having another rank. The data processor circuit stores an output version of the input tensor obtained from the tensor access operation circuit and sends the output version of the input tensor as multiple of units of input data to the at least one neural engine circuit. The at least one neural engine circuit performs at least convolution operations on the units of input data and at least one kernel to generate output data.