In instrumentation and embedded systems, what does it mean when a numeric or alphanumeric display is “multiplexed,” and which description best matches that behavior?

Introduction / Context:
Multiplexed displays reduce pin count and wiring by sharing segment or digit lines among multiple characters. Microcontrollers rapidly scan or time-share the drive signals so that, due to persistence of vision, users perceive a steady readout.

Given Data / Assumptions:

• Multiple digits or symbols share common segment lines.
• A controller activates one digit at a time at a high refresh rate.
• Human vision integrates the rapid updates.

Concept / Approach:
In multiplexing, the controller presents the appropriate segment pattern for one digit, enables that digit momentarily, then moves to the next, repeating quickly. The effect is a continuous multi-digit display with fewer physical connections than a fully parallel (non-multiplexed) solution, lowering cost and easing routing.

Step-by-Step Solution:
1) Partition the display into digits sharing segment lines.2) For each refresh slice, output the segment pattern for one digit and enable its common line.3) Cycle through all digits at, for example, hundreds of hertz.4) Net effect: a single display assembly presents multiple values or digits via time-sharing.

Verification / Alternative check:
Measure segment currents with an oscilloscope: each digit sees pulsed drive while the average brightness remains steady if refresh is fast enough.

Why Other Options Are Wrong:
(a) Describes a demultiplexer, not a multiplexed display.

(c) Generic switching statement; not about time-shared display driving.

(d) Arbitrary BCD limitation; multiplexing is not confined to four BCD lines.

(e) Opposite of multiplexing; dedicated continuous drive is non-multiplexed.

Common Pitfalls:
Driving digits too slowly causes flicker; driving too fast may reduce brightness due to duty cycle. Proper current and timing are essential.

Final Answer:
uses one display to present two or more pieces of information (time-shared driving of digits/segments)