Electronic Control Device Nonvolatile Memory Update Method
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Solution Overview
Problem
Existing electronic control devices face challenges in updating control software due to the need for rewriting the boot loader when the memory map changes, as the boot loader cannot rewrite itself.
Innovation Solution
The electronic control device is configured such that the control software and validity confirmation information are stored in a nonvolatile memory with separate storage areas, allowing for independent rewriting of the control software and address header during updates, without requiring the boot loader to rewrite itself.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the boot loader stores validity confirmation information internally, then validity confirmation can be performed, but the boot loader cannot rewrite itself when memory map changes
Solution Approach 1:
The patent divides the nonvolatile memory into separate storage areas: one for the boot loader and another for validity confirmation information. This segmentation allows the boot loader to remain static while enabling independent updates to validity confirmation information, resolving the contradiction between maintaining reliability through validity confirmation and achieving adaptability through self-rewritability.
Solution Approach 2:
The patent introduces an intermediary mechanism where validity confirmation information is stored separately in the nonvolatile memory rather than within the boot loader itself. This intermediary storage area allows the system to update validity information without rewriting the boot loader, enabling adaptability while preserving the boot loader's reliability.
2Adaptability or versatility
If the boot loader is rewritten when memory map changes, then adaptability is improved, but the complexity of the updating process increases
Solution Approach 1:
By segmenting the storage of boot loader and validity confirmation information into separate nonvolatile memory areas, the patent enables independent updates to validity information without requiring boot loader rewriting. This reduces updating process complexity while maintaining memory map flexibility.
Solution Approach 2:
The patent extracts validity confirmation information from the boot loader and stores it separately in the nonvolatile memory. This extraction allows the validity information to be updated independently without affecting or requiring rewriting of the boot loader, thereby reducing the complexity of the overall updating process while preserving adaptability.
3Device complexity
If validity confirmation information is stored in the boot loader, then the structure is simplified, but the boot loader cannot be updated independently
Solution Approach 1:
The patent applies segmentation by separating the storage locations of the boot loader and validity confirmation information within the nonvolatile memory. This maintains a relatively simple overall structure while enabling independent updates to validity information, resolving the contradiction between structural simplicity and independent update capability.
Solution Approach 2:
The patent introduces an intermediary storage area for validity confirmation information that is separate from the boot loader. This intermediary structure allows the validity information to be updated independently without complicating the boot loader itself, maintaining structural simplicity while achieving adaptability.
Data Source
AI summary
Provided is a technique for enabling software having different memory maps to be written in a nonvolatile memory of an electronic control device in reprogramming of control software.The electronic control device includes a microcomputer including a CPU and a nonvolatile memory. The nonvolatile memory includes activation software, control software, and validity confirmation information for confirming validity of the control software. A storage area of the validity confirmation information in the nonvolatile memory is different from a storage area of the activation software.