Digital pulse representation: In a coded digital word, does the bitstream consist of a sequence of defined HIGH and LOW voltage levels? Choose the best evaluation.

Introduction / Context:
Digital signals encode information using two defined voltage ranges to represent binary 0 and 1. Words, frames, and packets are built from sequences of these HIGH/LOW levels with clocking or timing recovery as needed.

Given Data / Assumptions:

• Binary logic levels are well-defined by family (CMOS, TTL, LVDS, etc.).
• Noise margins ensure robustness of HIGH/LOW interpretation.
• We consider standard single-ended or differential digital signaling.

Concept / Approach:
A coded group of pulses is literally a timed sequence where each interval maps to logic 0 (LOW) or logic 1 (HIGH). Even in differential systems (e.g., LVDS), the receiver detects two states based on differential polarity, which are still “two levels.”

Step-by-Step Solution:

Verification / Alternative check:
Oscilloscope traces of digital buses show time-quantized pulses between two level ranges. Eye diagrams reinforce the two-level detection concept.

Why Other Options Are Wrong:
Incorrect: Conflicts with the definition of binary signaling.

“Only for synchronous/low frequency” adds constraints that are not fundamental to the two-level representation.

Common Pitfalls:
Confusing line coding variations with multi-level logic. Most general-purpose digital circuits still interpret two states per line.

Final Answer:
Correct