問62
頻出度★☆☆
コンピュータ内部において, CPU とメモリの間やCPU と入出力装置の間などで, データを受け渡す役割をするものはどれか。
平成26年度 春期 ITパスポート試験 問62
テクノロジ系コンピュータ構成要素 › プロセッサ
This question's explanation and your answers so far.
解説
問 62
- ア
正解 The correct answer is ア, the bus. A bus is a shared transmission path inside a computer that links components such as the CPU, main memory, and input/output devices so that data and signals can be exchanged between them. The role described in the question, transferring data between the CPU and memory and between the CPU and input/output devices, is exactly what a bus does. Buses are commonly explained by the type of signal they carry: an address bus that specifies the location (address) to read from or write to, a data bus that carries the data itself, and a control bus that sends control signals such as read and write. They are also distinguished by the range they connect, for example a fast internal bus linking the CPU and main memory (the system bus) and an external bus connecting expansion slots and peripheral devices (the expansion bus). It is also important that the larger the number of bits carried at one time (the bus width) and the number of transfers per second (the bus clock), the higher the transfer performance, which affects the processing speed of the whole computer.
Incorrectイ
A hub is a concentrator device that gathers the communication cables of several devices at one point in a LAN so that they can be interconnected; it is a network device located outside the computer. What the question asks about is a transmission path inside a single computer that links the CPU with memory or input/output devices, so the scope is different.
Incorrectウ
A port refers to a connector (interface) used to attach peripheral devices or cables to a computer, as in a USB port or a LAN port. It is ultimately just a socket for connecting equipment, not the internal transmission path itself that carries signals between the CPU and memory. The word is also used for the port number that identifies an application in TCP/IP communication, but neither meaning matches what the question asks.
Incorrectエ
A router is a device that interconnects different networks (LAN to LAN, LAN to the Internet, and so on), looks at the destination IP address, and forwards packets along an appropriate route. This too works between networks rather than inside a computer, so it is not what transfers data between the CPU and memory.
ここがポイント
- A bus is a shared transmission path that links components such as the CPU, memory, and input/output devices inside a computer. It is divided by the signals it carries into the address bus, the data bus, and the control bus; the larger the bus width (the number of bits carried at one time) and the bus clock, the higher the transfer performance.
- Hubs and routers are devices that connect networks outside the computer, and a port is a connector for attaching peripheral devices; none of them is a transmission path inside the computer. For terminology questions, it helps to judge by sorting out where the term operates, inside the computer or on the network.
用語