Depthwise Separable Convolution Accelerator With Multi-Buffer Memory

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Solution Overview

Problem

Existing accelerators for neural networks, such as TPU, DaDianNao, and EIE, are not suitable for low-end edge devices due to high memory requirements, and even when computational speed is enhanced, performance is not improved due to significant memory access latency.

Innovation Solution

An accelerator system with an off-chip memory, buffers, and a bus architecture that reduces memory access latency by using multiple buffers to temporarily store data and instructions, and performs depthwise separable convolution to enhance processing unit utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If accelerators use large capacity on-chip memory or frequent off-chip memory access to enhance computational speed, then computational throughput is improved, but memory access latency increases and performance is not relatively improved

Engineering Contradiction:
Improvecomputational throughputVSAvoidmemory access latency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent segments the memory system into multiple buffers (first buffer, second buffer, third buffer, fourth buffer) distributed across different locations (off-chip and on-chip). This segmentation allows parallel data loading and processing, where different buffers can simultaneously hold input data, weights, intermediate results, and output data, thereby reducing memory access latency while maintaining high computational throughput.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-loading data into buffers before computation is needed. The first buffer pre-stores input data, the second buffer pre-loads instructions, and the fourth buffer prepares to store output data. This preliminary data preparation in buffers reduces waiting time during actual computation, effectively reducing memory access latency while maintaining high throughput.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If accelerators are designed for high computational speed, then processing capability is enhanced, but device complexity increases making them unsuitable for low-end edge devices

Engineering Contradiction:
Improveprocessing capabilityVSAvoidmemory capacity requirement
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent transitions from a single large on-chip memory architecture to a multi-dimensional buffer distribution architecture. Instead of using one large memory block, the system distributes data across multiple smaller buffers located in different dimensions (off-chip first buffer, on-chip second/third/fourth buffers). This dimensional redistribution reduces the complexity of any single memory component while maintaining overall processing capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces buffers as intermediary components between the computation units and the main memory systems. These buffers act as mediators that temporarily hold data close to the computation units, reducing the need for frequent access to large capacity memory. This intermediary buffer architecture reduces device complexity while preserving processing capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of time

If multiple buffers are introduced to reduce memory access latency, then performance is improved, but device complexity increases

Engineering Contradiction:
Improvememory access latencyVSAvoidbuffer architecture complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent designs the buffer architecture with multi-functionality where the same buffer structure can serve multiple purposes: the first buffer handles input data, the second buffer handles instructions, the third buffer handles intermediate data transfer, and the fourth buffer handles output data. This universal buffer design pattern reduces overall system complexity by using a standardized multi-functional approach rather than specialized components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS12602336B2Accelerator system and method to execute depthwise separable convolution
Publication Date: 2026.04.14 NAT CHENG KUNG UNIV
  • US12602336B2 patent drawing
  • US12602336B2 patent drawing
  • US12602336B2 patent drawing

AI summary

An accelerator system includes an off-chip memory, a bus, and an accelerator. The off-chip memory includes a first buffer. The accelerator includes a second buffer, a third buffer, a fourth buffer, an instruction fetching module, a load module, a storage module, a convolution control module, and a computation module. The instruction fetching module fetches instructions from the off-chip memory via the bus. The load module loads input data from the off-chip memory via the bus. The storage module stores the output data to the off-chip memory via the bus. The computation module performs convolution computations based on the input map and multiple kernels allocated by the convolution module. In response to loading the input data or instruction from the off-chip memory, the requested input data or instruction is transferred from the off-chip memory and temporarily stored in the first buffer.