Benefits of USB

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Quick Questions

Shade in the A or B circle for each question.

1. Which statement describes a benefit of USB being a standard connector?

A Each device needs its own special port made only for that device

B One type of port can be used by many different devices, such as keyboards, mice and printers

2. What happens when a USB device is plugged into a computer?

A The computer automatically detects the device and can load a driver for it

B The user must restart the computer so it can find the device

3. An old USB 2.0 flash drive is plugged into a newer USB 3.0 port. What is likely to happen?

A It still works because USB is backwards compatible

B It will not work because the port is a newer version

4. Which is a benefit of USB when using a small device like a phone or a flash drive?

A The cable can supply power to the device, so it may not need its own power supply

B The cable can only carry data, so every device needs its own battery or plug

5. Which describes how USB sends data quickly?

A It uses parallel transmission, sending all bits side by side, which causes skew

B It uses fast serial transmission, sending bits one after another along a wire

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1USB_PORT <- keyboard, mouse, printer		AUSB uses a standard connector, so one type of port works with many devices.
2IF device_plugged_in THEN detect(device)		BUSB2_DEVICE -> USB3_PORT : works
3Older USB devices still work when plugged into newer USB ports (backwards compatible)		Ccable.carry(data, power)
4The USB cable supplies power to the device as well as carrying data		DThe computer recognises the device automatically when it is connected
5User must tell the computer a USB device is connected		EOne standard connector works with many different types of device
6Every device needs a different type of USB connector		FUSB devices are detected automatically. The user does not need to tell the computer.

Definitions

USB benefits

Fill in the Blanks

Complete each line of code by filling in the missing parts.

plug mouse INTO ___ port

IF pluggedIn = TRUE THEN detected ← ____ ENDIF

IF deviceVersion __ portVersion THEN works ← TRUE ENDIF

device.power ← usbCable._____

mode ← ______ speed ← FAST sendBits(mode, speed)

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A device = "keyboard"

B connector = "unique shape"

C print(device, connector)

Question 2

A plug_in("mouse")

B manual_setup = True

C if not manual_setup:

D print("Auto detected")

Question 3

A device = 2 # older device

B port = 1 # newer port

C ok = device <= port

D print(ok)

Question 4

A usb_gives = "data only"

B device = "phone"

C print(device, usb_gives)

Question 5

A usb_mode = "serial"

B bits_at_once = 1

C speed = "very slow"

D print(usb_mode, speed)

Answer Key

Benefits of USB

Section A: Quick Questions

B — One type of port can be used by many different devices, such as keyboards, mice and printers

A — The computer automatically detects the device and can load a driver for it

A — It still works because USB is backwards compatible

A — The cable can supply power to the device, so it may not need its own power supply

B — It uses fast serial transmission, sending bits one after another along a wire

Section B: Match the Pairs

USB_PORT <- keyboard, mouse, printer → One standard connector works with many different types of device

IF device_plugged_in THEN detect(device) → The computer recognises the device automatically when it is connected

Older USB devices still work when plugged into newer USB ports (backwards compatible) → USB2_DEVICE -> USB3_PORT : works

The USB cable supplies power to the device as well as carrying data → cable.carry(data, power)

User must tell the computer a USB device is connected → USB devices are detected automatically. The user does not need to tell the computer.

Every device needs a different type of USB connector → USB uses a standard connector, so one type of port works with many devices.

Section C: Definitions

USB benefits — One standard connector fits many devices, devices are detected automatically, older devices work in newer ports, power comes through the cable, and fast serial transfer is used.

Section D: Fill in the Blanks

plug mouse INTO USB port

IF pluggedIn = TRUE THEN
   detected ← TRUE
ENDIF

IF deviceVersion <= portVersion THEN
   works ← TRUE
ENDIF

device.power ← usbCable.power

mode ← SERIAL
speed ← FAST
sendBits(mode, speed)

Section E: Spot the Error

B — USB uses one standard connector for many different devices. It should be connector = "standard USB", not a unique shape for each device.

B — USB devices are detected automatically, so the user does not need to set them up by hand. manual_setup should be False.

B — Backwards compatibility means older devices work in newer ports. The newer port needs a higher version number than the older device, so it should be port = 3.

A — A USB cable supplies power as well as carrying data. It should be "power and data", not data only.

C — USB uses serial transmission and transfers data quickly. The speed should be "fast".