Vehicular Display Memory Partitioning for Fewer Nonvolatile Writes
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Solution Overview
Problem
Existing vehicular display devices face an increased risk of incorrect data storage due to excessive writes to nonvolatile memory when saving vehicle information, necessitating a reduction in the number of writes to such memory.
Innovation Solution
The vehicular display device employs a dual-memory system with a smaller volatile second save memory and a nonvolatile first save memory, utilizing an on/off power supply to manage power distribution and separate vehicle information for storage between these memories based on update frequency before entering a power-saving mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all vehicle information is saved in a single nonvolatile memory, then data retention is ensured, but the number of writes increases causing storage reliability to deteriorate
Solution Approach 1:
The patent divides the save memory into two distinct parts: a first save memory (nonvolatile) and a second save memory (volatile). This segmentation allows different types of vehicle information to be stored in different memory types based on their access and retention requirements, thereby reducing write operations to the nonvolatile memory while ensuring data retention where needed.
2Reliability
If a smaller volatile memory is used for frequently updated data, then nonvolatile memory write operations are reduced, but data loss risk increases when power is lost
Solution Approach 1:
The patent applies local quality by assigning different memory characteristics to different data types. Frequently updated information that can tolerate power loss is stored in the volatile second save memory, while critical information requiring persistence is stored in the nonvolatile first save memory. This localized optimization resolves the contradiction by matching memory properties to data requirements.
Data Source
AI summary
To provide a vehicular display device capable of reducing the number of times save vehicle information is written into a nonvolatile memory. When a vehicle travel end operation is performed, an turns off a first power supply circuit and a second power supply circuit and performs data saving processing before shifting to a power saving mode. In the data saving processing, a part of vehicle information stored in a RAM is separated to be separately stored in a ROM and an in-core RAM (included in an internal memory of a second processor core) to which power is constantly supplied, as save-required-data (save vehicle information).