Display system buses in multiplexed readouts: Evaluate the statement — “The digit bus and the display (segment) bus are common sets of conductors shared by the digit storage registers and the seven-segment display segments, respectively.”

Introduction / Context:
Multiplexed display systems reduce wiring and driver count by sharing signals among digits. Two common buses exist: a digit-select bus (activating which digit is currently lit) and a segment (display) bus that carries segment data a–g (and possibly DP). Understanding these shared conductors is vital for designing efficient user interfaces on embedded systems.

Given Data / Assumptions:

• Seven-segment LED or LCD digits are multiplexed.
• Digit-select lines enable one digit at a time.
• Segment lines are shared across all digits.

Concept / Approach:
In time-multiplexing, the controller presents segment data on a common segment bus while enabling exactly one digit through the digit bus (digit enables). Rapid scanning creates the illusion that all digits are lit simultaneously. Both sets of lines are shared: the digit bus distributes enables; the segment bus carries the segment pattern.

Step-by-Step Solution:

Verification / Alternative check:
Observe with an oscilloscope or logic analyzer: digit lines show periodic enables; segment lines show patterns synchronized with each digit’s time slice. Persistence of vision yields a stable multi-digit readout.

Why Other Options Are Wrong:

• Incorrect: Contrary to well-established multiplexing practice.
• True only for LCDs: LEDs and LCDs both use shared buses in multiplexing.
• Depends on open-collector drivers: Driver type does not change the bus-sharing concept.
• Only valid with separate encoders: Encoders are optional; microcontrollers can drive segment data directly.

Common Pitfalls:
Insufficient refresh rate causing flicker; ghosting due to slow drivers; forgetting current-limiting resistors per segment; misordering segment labels.

Final Answer:
Correct