Digital fundamentals — latch/flip-flop taxonomy: Is an S–R (Set–Reset) flip-flop an example of a bistable multivibrator circuit?

Introduction / Context:
Multivibrators are classified by the number of stable states: bistable (two stable states), monostable (one stable state), and astable (no stable state). The S–R flip-flop is a foundational storage element in digital electronics and is the canonical example of a bistable device.

Given Data / Assumptions:

• S–R flip-flop implemented with cross-coupled gates or latches.
• Two stable outputs: Q = 0 or Q = 1.
• External inputs can set or reset the state.

Concept / Approach:
A bistable multivibrator remains indefinitely in its current state until an input causes a transition to the other state. The S input forces Q to 1 (set), and the R input forces Q to 0 (reset), subject to implementation details and invalid combinations (e.g., S = R = 1 in simple NOR-latch forms). This persistent storage is why the S–R flip-flop is used as a memory element.

Step-by-Step Solution:

Verification / Alternative check:
Truth tables and timing diagrams of S–R latches and flip-flops demonstrate two stable states and edge/level-triggered control. Datasheets list these as bistable elements.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing “latch” (level-sensitive) with “flip-flop” (edge-triggered); ignoring invalid input conditions in simple S–R latch implementations.

Final Answer:
Yes, an S–R flip-flop is a bistable multivibrator