Vehicle Display Device Microcomputer Timer Synchronization

Solution Overview

Problem

Existing vehicle display devices face challenges in synchronizing the timer counters of main and sub microcomputers, leading to inefficiencies in communication responsiveness, which can be costly to address with dedicated signal lines.

Innovation Solution

The vehicle display device synchronizes the timer counters of the main and sub microcomputers using a chip select signal within the SPI communication method, eliminating the need for a dedicated signal line by switching the chip select signal from Lo to Hi or Hi to Lo levels to align the count values of the timer counters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a dedicated signal line is added between the main microcomputer and sub microcomputer to synchronize timer counters, then communication responsiveness is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecommunication responsivenessVSAvoidmanufacturing cost

Core Design Contradiction:

SpeedVSEase of manufacture

Solution Approach 1:

The chip select signal line is made multi-functional by having it serve both its original purpose of selecting the sub microcomputer for data transmission and an additional purpose of synchronizing the timer counters between main and sub microcomputers. This eliminates the need for a separate dedicated synchronization signal line, thereby improving communication responsiveness without increasing manufacturing cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If timer counters of main and sub microcomputers are not synchronized, then device complexity is reduced, but communication efficiency deteriorates

Engineering Contradiction:

Improvesignal line configurationVSAvoidcommunication efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The chip select signal line is made multi-functional by having it serve both its original purpose of selecting the sub microcomputer for data transmission and an additional purpose of synchronizing the timer counters between main and sub microcomputers. This eliminates the need for a separate dedicated synchronization signal line, thereby improving communication responsiveness without increasing manufacturing cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3446927B1Vehicle display device

Publication Date: 2022.11.23 NIPPON SEIKI CO LTD

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AI summary

Provided is a vehicle display device such that the responsiveness of communication between a main microcomputer and a sub microcomputer is improved. The vehicle display device (10) is equipped with a main microcomputer (20) that generates information data and a sub microcomputer (30) that generates an image to be displayed on a display element (40) on the basis of the information data. Between the main microcomputer (20) and the sub microcomputer (30), at least a signal line for data transmission and a signal line for chip select signal transmission are connected so as to allow communication between the main microcomputer (20) and the sub microcomputer (30). The vehicle display device (10) synchronizes a first timer counter (22) counted by the main microcomputer (20) and a second timer counter (32) counted by the sub microcomputer (30), in response to the tip select signal transmitted to the sub microcomputer (30) by the main microcomputer (20).