SarkariResultOutAdditional Assistant Engineer (Electrical) · 2026

Previous Year Question

What essential condition must be fulfilled for synchronous serial communication to function correctly in the 8051 microcontroller?

Only ASCII data should be sent
Data must be sent at a constant baud rate (bits per second)
Both sender and receiver must use a common clock signal
Use of a parity bit is mandatory

Correct answer: C

Explanation

Synchronous serial transfer uses a shared timing reference so that both ends sample each bit at the intended instant. Therefore sender and receiver must operate with a common clock relationship.

Step-by-step solution

Synchronous Communication Clock explanatory diagram

Correct Answer

C — Both sender and receiver must use a common clock signal

Explanation

Synchronous serial transfer uses a shared timing reference so that both ends sample each bit at the intended instant. Therefore sender and receiver must operate with a common clock relationship.

Key Concept

Synchronous Communication Clock

Exam Point

Synchronous = shared clock; asynchronous = agreed baud timing without a shared data clock.

Exam tip

Synchronous = shared clock; asynchronous = agreed baud timing without a shared data clock.

Quick method

Synchronous = shared clock; asynchronous = agreed baud timing without a shared data clock.