Priority Handling — Multiple Active Inputs When two or more inputs to a system are asserted at the same time, which technique resolves which input should be serviced or encoded first?

Introduction / Context:
Digital systems often face contention when multiple request or interrupt lines are active simultaneously. An ordered method is needed to decide which request is recognized first or which input gets encoded. The circuit or algorithm that enforces this order is a priority scheme.

Given Data / Assumptions:

• At least two inputs can be active at the same time.
• The system must select one to service or encode, based on a predefined precedence.
• We are considering combinational selection, not queuing in time.

Concept / Approach:
A priority encoder outputs the binary code of the highest-priority active input, ignoring lower-priority active lines. This differs from FIFO (a temporal queue that services requests in arrival order) and ripple blanking (a display feature used to suppress leading zeroes). Priority schemes are common in interrupt controllers and bus arbiters.

Step-by-Step Solution:
Identify simultaneous-assertion scenario.Apply priority rule: highest-priority input wins.Encode or route only the winning input; others are masked.Thus, the correct process is priority encoding.

Verification / Alternative check:
Examine a 74xx148 (8-to-3 priority encoder): when multiple inputs are LOW (active), the output code corresponds to the highest-priority position as defined by the device.

Why Other Options Are Wrong:

• first-in, first-out processing: A queue discipline over time, not simultaneous selection.
• ripple blanking: A seven-segment display feature, not a contention resolver.
• FIFO or priority (either/or): Mixing unrelated mechanisms; the correct resolution method here is specifically priority encoding.

Common Pitfalls:
Assuming FIFO solves simultaneous assertion without serialization hardware; FIFO requires sequential arrival, not concurrent signals.

Final Answer:
priority encoding