Q.Mention two differences between microprocessor and microcontroller.

A microprocessor is only a CPU that must be connected to external memory, I/O and timers, whereas a microcontroller integrates the CPU together with memory, I/O ports and timers on a single chip.

[!ANSWER]

(1) A microcontroller has on-chip ROM, RAM, I/O ports and timers, while a microprocessor needs these connected externally. (2) A microprocessor is a general-purpose computing device, whereas a microcontroller is meant for dedicated/embedded control applications with lower cost and power.

[!TLDR]

A microcontroller is a complete computer-on-a-chip for embedded control, while a microprocessor is only the processing unit that must be surrounded by external support chips.

A microprocessor (for example the 8085 or 8086) contains only the CPU — the ALU, registers and control unit. To build a working system, memory (ROM/RAM), I/O ports, timers and serial ports must be added externally and joined through address, data and control buses. This makes it flexible and general-purpose, which is why it is used in computers.

A microcontroller (for example the 8051) packs the CPU, a fixed amount of on-chip ROM and RAM, I/O ports, timers/counters and a serial port into one IC. This makes it compact, low-cost and low-power, and ideal for a single dedicated task in embedded systems such as appliances and instruments.

[!ANSWER]

Two differences: (1) memory, I/O and timers are built into a microcontroller but external to a microprocessor; (2) a microprocessor is general-purpose (computers) whereas a microcontroller is application-specific (embedded control).

[!NOTE]

In this textbook's Two-marks Question Bank the printed numbering physically skips 13, 14 and 15 — it jumps directly from question 12 to question 16. The printed numbers are preserved exactly here; questions 13-15 are absent in the book, not omitted in transcription.