Which statement best differentiates a microcontroller from a microprocessor?

• A. A microcontroller integrates CPU, memory, and peripherals on one chip for embedded control; a microprocessor is a standalone CPU requiring external memory and peripherals for larger computing tasks.
• B. A microcontroller uses external memory, while a microprocessor has all components on-chip.
• C. A microcontroller is only used in desktop computing, while a microprocessor is used in embedded systems.
• D. A microcontroller cannot run software, whereas a microprocessor can.

Answer: (A)

The key idea is how integration and intended use set microcontrollers apart from microprocessors. A microcontroller is built as a compact, self-contained control unit for embedded tasks: the CPU, memory (often on-chip), and various peripherals like timers, ADCs, and GPIO are all on one chip. This on-chip integration makes it ideal for dedicated devices that need a small, cost-effective, real-time controller. A microprocessor, by contrast, is mainly the central processing unit; it usually requires separate memory and peripheral hardware to form a complete system, because it’s designed for general-purpose computing where you add the needed components.

That’s why the statement describing on-chip integration with embedded control versus needing external memory and peripherals for larger tasks is the best fit. The other options misstate where memory typically goes, the kinds of applications, or whether these devices can run software. Microcontrollers commonly run software/firmware, and microprocessors are used in many embedded systems too, but with different system architectures.