Microcontroller building blocks Which of the following do microcontrollers typically contain on-chip?

Introduction / Context:
Unlike general-purpose microprocessors that often require many external components, microcontrollers integrate multiple subsystems on a single chip to enable compact embedded designs. This question tests recognition of what is typically integrated.

Given Data / Assumptions:

• Microcontroller = CPU core plus essential memory and peripherals.
• Target applications include control and real-time tasks.
• Integration reduces board size, cost, and power.

Concept / Approach:
A typical microcontroller integrates a CPU, volatile memory (RAM) for variables and stack, and nonvolatile program memory (ROM/Flash). Many also include timers, GPIO, ADC/DAC, serial interfaces, and more, forming a complete embedded system on chip.

Step-by-Step Solution:

Verification / Alternative check:
Review any mainstream MCU family block diagram (for example, 8051 derivatives, AVR, PIC, ARM Cortex-M): CPU + RAM + Flash are standard.

Why Other Options Are Wrong:

• CPUs / RAM / ROM individually are components; microcontrollers typically include all, not just one.

Common Pitfalls:
Confusing microcontrollers with microprocessors that may require external RAM/ROM and peripherals.

Final Answer:
all of the above