Cambridge IGCSE Computer Science · Syllabus 0478 · Hardware
Microprocessor
What is Microprocessor?
A type of integrated circuit on a single chip that contains the processing functions of a CPU; microprocessors are used both in general-purpose computers and in embedded systems.
This definition is part of the Hardware chapter in Cambridge IGCSE Computer Science.
Common mistakes with Microprocessor
- 2. “A microprocessor is any electronic chip.” Why wrong Memory chips, sound chips and graphics chips are all integrated circuits, and none of them is a microprocessor. Correct model A microprocessor is a type of integrated circuit — one that contains the processing functions of a CPU on a single chip. Every microprocessor is an integrated circuit; not every integrated circuit is a microprocessor. Exam-safe “A microprocessor is a type of integrated circuit on a single chip that contains the processing functions of a CPU.” Check: is a RAM chip a microprocessor?No. It is an integrated circuit, but it stores data rather than containing the processing functions of a CPU.
- 16. “A sensor makes the final control decision.” Why wrong A sensor has no stored target value and nothing to compare against. It cannot know whether a reading is acceptable. Correct model A sensor measures a physical property and produces data. A microprocessor compares that data with a stored value and decides. If a condition is met, a signal is sent to an actuator or another output device. Exam-safe “The sensor sends readings to the microprocessor, which compares them with a stored value and, if necessary, sends a signal to an actuator.” Check: fill the gaps — sensor → ______ → ______.sensor → microprocessor (compares with a stored value) → actuator (or another output device).
- 17. “An actuator is an input device.” Why wrong It has the direction backwards. An actuator receives a signal; it does not produce data for the computer. Correct model An actuator is an output device that converts a control signal from the computer into a physical action — movement, opening or closing, switching on or off. Exam-safe “An actuator is an output device that converts a signal from the microprocessor into a physical action.” Check: in a greenhouse system, which is the sensor and which is the actuator — the device that measures the temperature, or the motor that opens the vent?The device that measures the temperature is the sensor (input); the motor that opens the vent is the actuator (output).