Bus Transceiver Mode Switching Within the Serial Bit Stream

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Solution Overview

Problem

In-vehicle network busses, such as CAN and CAN FD, face limitations in data rate, requiring improved communication speed between devices, and existing solutions often necessitate additional control signals and pins, increasing cost and complexity.

Innovation Solution

A bus device with a bus protocol controller and transceiver that switches between different operating modes by embedding switching signals within the serial bit stream, allowing changes in bit coding schemes and bit rates, thereby enhancing data transmission rates without additional control signals, and supporting pin-compatible solutions with older devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If additional control signals and pins are added to increase data transmission rates, then communication speed improves, but device complexity and cost increase

Engineering Contradiction:
Improvecommunication speedVSAvoiddevice complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent combines the data transmission function and mode switching function into a single channel. The transceiver switches between different operating modes (classic CAN, CAN FD, CAN XL) by detecting switching signals embedded within the data stream itself, eliminating the need for separate control signals and pins for mode selection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The transceiver is designed with multi-functionality to handle multiple CAN protocols (classic CAN, CAN FD, CAN XL) and operating modes within a single device. The same physical interface and control mechanism support different data rates and coding schemes, making the device adaptable to various communication requirements without additional hardware.

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

2Speed

If additional control signals and pins are added to increase data transmission rates, then communication speed improves, but cost increases

Engineering Contradiction:
Improvedata transmission rateVSAvoidcost
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The patent merges the mode selection control function into the data transmission channel. By embedding switching signals within the existing data stream, the invention eliminates the need for additional control pins and signals, reducing hardware complexity and manufacturing cost while maintaining the capability to switch between different data transmission modes.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If switching signals are embedded within the serial bit stream, then additional control signals are eliminated, but detection complexity increases

Engineering Contradiction:
Improvecontrol signal complexityVSAvoidswitching signal detection
Core Design Contradiction:
Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent uses distinct signal patterns (analogous to color changes) to represent different operating modes. Specific bit patterns or sequences within the data stream indicate mode switching requirements, allowing the transceiver to detect and respond to mode changes by recognizing these predefined patterns without requiring complex external control logic.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP3691197B1Bus device and method for operating a bus device
Publication Date: 2021.12.29 NXP BV
  • EP3691197B1 patent drawingFigure 1
  • EP3691197B1 patent drawingFigure 2
  • EP3691197B1 patent drawingFigure 3~5

AI summary

The present disclosure relates to a bus device and a corresponding bus system. Furthermore, the present disclosure relates to a corresponding method of operating a bus device. In accordance with a first aspect of the present disclosure there is provided a bus device comprising a bus protocol controller with a transmit data output and a bus transceiver with a transmit data input coupled to the transmit data output of the bus protocol controller, wherein the bus protocol controller is configured to provide a serial bit stream designated for transmission through a bus via the transmit data output of the bus controller and via the transmit data input to the bus transceiver and to provide a switching signal within the serial bit stream, and wherein the bus transceiver is configured to switch between different operating modes in response to the switching signal.