If an input action is initiated by a signal transition (a change from 0→1 or 1→0) rather than by a sustained level, that input is said to be ________.

Introduction / Context:
In digital electronics, how a device responds to a control signal—on an edge or on a level—shapes timing behavior and design methodology. Edge-triggering provides precise timing points, whereas level-sensitive control allows action over a window while the level is asserted.

Given Data / Assumptions:

• The device action occurs upon a transition of the control input (rising or falling edge).
• While the input remains high or low, no additional action occurs until the next edge.
• Terms used should reflect standard engineering vocabulary.

Concept / Approach:
“Edge-triggered” describes activation tied to a change in the control signal. Typical examples are flip-flops that sample data on rising_edge(clk) or falling_edge(clk). In contrast, “level-sensitive” latches respond as long as the enable remains active. Pulse-triggered may describe one-shots that respond to a narrow pulse, but the defining concept here is the edge itself.

Step-by-Step Solution:

Verification / Alternative check:
Timing diagrams of standard flip-flops show state changes only at clock edges. No changes occur while the clock level is steady, confirming edge sensitivity.

Why Other Options Are Wrong:
“hair-triggered” is not a formal term. “line-triggered” is ambiguous and nonstandard. “pulse-triggered” emphasizes a pulse occurrence rather than the edge itself; many edge-triggered circuits do not require a narrow pulse, just a qualifying edge.

Common Pitfalls:
Confusing edge-triggered flip-flops with level-sensitive latches, leading to unintended transparency and race conditions if misapplied.

Final Answer:
edge-triggered