RISC-V PWM Control With Custom Instructions and Lower Processor Load

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional pulse width modulation (PWM) control systems using x86 and ARM architectures suffer from low efficiency, high instruction redundancy, large area and power consumption, and high licensing fees due to their need for backward compatibility and extensive instruction sets.

Innovation Solution

A PWM control system based on the RISC-V open-source instruction set architecture, allowing customization of operations, which includes a processor and a pulse modulation interface module to generate and output preset waveforms using customized instructions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional x86 and ARM architectures are used for PWM control, then universal compatibility is achieved, but control efficiency is low and instruction redundancy is high

Engineering Contradiction:

Improvearchitecture compatibilityVSAvoidPWM control efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the instruction set architecture by separating general-purpose instructions from PWM-specific instructions. The PWM control function is isolated into dedicated hardware modules (counter module, waveform generation module, comparison module) that operate independently from the main processor, allowing PWM operations to execute in parallel without blocking other processor tasks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a dedicated PWM control module as an intermediary between the processor and output peripherals. This module includes specialized registers (PWM control register, duty cycle register, period register) that act as intermediaries to configure and control PWM parameters without requiring the processor to execute multiple general-purpose instructions for each PWM parameter adjustment.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If commercial architectures with backward compatibility are used, then legacy support is maintained, but processor area and power consumption increase

Engineering Contradiction:

Improvebackward compatibilityVSAvoidprocessor power consumption

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by stationary object

Solution Approach 1:

The patent extracts the PWM control functionality from the general-purpose processor core and implements it as a separate dedicated hardware module. This extraction removes the need for the processor to maintain extensive instruction sets and compatibility layers for PWM-specific operations, reducing the active transistor count in the processor path and thereby lowering dynamic power consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The PWM control module is designed to be self-configuring through dedicated registers that directly map to hardware parameters. Once configured via simple register writes, the module autonomously generates PWM waveforms without requiring continuous processor intervention or complex instruction execution, enabling the system to enter low-power states while maintaining PWM functionality.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If multiple instructions are used for PWM output operations, then compatibility with general-purpose processors is maintained, but control complexity increases

Engineering Contradiction:

Improveprocessor compatibilityVSAvoidinstruction sequence complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple PWM control functions (counter increment, comparison operation, waveform generation, duty cycle adjustment) into a single integrated PWM control module. This consolidation allows all PWM parameters to be configured through a unified set of dedicated registers, eliminating the need for complex multi-instruction sequences and reducing software complexity while maintaining processor compatibility through standard memory-mapped I/O.

Inventive Principle:

Principle #5Merging (Combining)

4Productivity

If RISC-V customized instructions are used, then PWM control efficiency is improved, but hardware customization is required

Engineering Contradiction:

ImprovePWM control efficiencyVSAvoidhardware customization

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal PWM control module that can serve multiple PWM channels and various waveform types (PWM, PAM, unipolar/bipolar waves) through a single standardized hardware design. The module uses configurable registers that can be programmed to achieve different PWM functionalities without requiring separate custom hardware for each application, thus improving efficiency while minimizing hardware customization requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12423105B2Multi-channel pulse modulation control system, device, and method based on RISC-V custom instructions

Publication Date: 2025.09.23 SHENZHEN POWER SUPPLY BUREAU

AI summary

This application relates to a pulse modulation control system, device, and method. The system includes a processor based on a RISC-V open-source instruction set architecture and a pulse modulation interface module. The processor is configured to receive an operation instruction of a user, and generate a data signal based on the operation instruction. The pulse modulation interface module is connected to the processor, and is configured to receive the data signal and output a preset waveform based on the data signal. Based on the RISC-V open-source instruction set architecture, the user may customize operations, which improves efficiency and flexibility of a pulse modulation process, and optimizes power consumption.