問28
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組込みシステムの特徴として, 最も適切なものはどれか。
平成21年度 秋期 ITパスポート試験 問28
This question's explanation and your answers so far.
解説
問 28
Incorrectア
It is wrong because it asserts that a dedicated OS must be used. Embedded systems often use a real-time OS (RTOS), but it is also common to configure a general-purpose OS such as Linux for embedded use, and it is quite ordinary to run only a control program directly with no OS at all. Development is also generally done with cross-development tools on an ordinary PC, so a dedicated OS cannot be called a requirement.
Incorrectイ
The claim that a network connection is required for operation does not hold. There are countless embedded systems that are not connected to a network, such as rice cookers, microwave ovens, calculators, and traditional home appliances. In recent years more embedded systems connect to networks, as in IoT devices, but that is a choice driven by the intended use, not a requirement for operation.
Incorrectウ
The claim that no user interface is needed is wrong. It is true that embedded systems handle control inside a device, but many of them have operation and display parts such as buttons, touch panels, LCDs, LEDs, and buzzers, and interact with users. Car navigation systems, digital cameras, and multifunction printers are typical examples with rich user interfaces, so saying a UI is unnecessary is an overgeneralization.
- エ
正解 エ is correct. An embedded system is a computer system built into a device such as a home appliance, car, industrial machine, or office machine, and designed to realize that device's specific functions. Unlike a general-purpose PC or server, it only has to handle a predetermined set of uses, so the hardware (microcontroller, dedicated LSI, sensors, actuators, and so on) is specialized to fit the required performance, power consumption, cost, and size, and the software that runs on it (firmware) is also written specifically for that device. In other words, エ's statement that it consists of specialized hardware and software captures the most essential characteristic of an embedded system.
ここがポイント
- An embedded system is a combination of hardware and software (firmware) specialized for a specific use and built into a specific device. Remember it in contrast with general-purpose computers.
- When a choice asserts that something is always required or always unnecessary, look for counterexamples. Whether a dedicated OS, a network connection, or a user interface is present all depends on the intended use, and none of them is a requirement for an embedded system.
用語