Universal Serial Bus (USB)
Computer Science: Cambridge International GCSE, topic 1.2.3
Universal Serial Bus (USB)
USB connects a wide range of electronic devices (like keyboards, mice, printers, and external hard drives) to computers. It is one of the most common input/output devices.
How does USB transmit data?
- USB uses serial data transmission.
- This means data is sent one bit at a time along a single wire.
- A USB cable contains multiple wires: two for power and two for data.
- The data wires are used for full-duplex transmission, meaning data can be sent and received at the same time.
Benefits of USB
- Universal standard:
- USB is a widely recognised standard, allowing great compatibility between devices from different manufacturers.
- Plug and play:
- USB devices are automatically recognised by a computer's operating system when plugged in.
- Hot-swappable:
- USB can be plugged in and removed without having to switch off the computer.
More benefits of USB
- Power supply:
- USB ports can provide electrical power to devices, eliminating the need for a separate power cable.
- Speed:
- Newer versions of USB (USB 3.0, USB-C) allow faster data transfer.
- Reliability:
- USB includes error checking in data packets.
Drawbacks of USB
- Cable length:
- The standard USB cable is limited to a few metres – beyond this, data can become corrupted.
- Transfer speed:
- USB can still be slower than other specialised interfaces in some professional applications.
- Connector variations:
- There are many types of USB connectors (e.g. USB-A, USB-B, USB-C), which can be confusing for users.
- Newer USB types (e.g. USB-C) may not fit older ports.
Test yourself on Universal Serial Bus (USB)
What type of data transmission does USB use?
Which feature of USB allows devices to be recognised automatically when connected to a computer?