Memory behavior in digital circuits: Consider latches and flip-flops that exhibit the property of memory (storing a logic state). Do such memory circuits normally revert to an original state when the input stimulus is removed, or do they retain the last stored state until an explicit reset or a new triggering input is applied?

Introduction / Context:
Digital memory elements such as latches and flip-flops are designed to store information. The statement claims that circuits with memory normally revert to their original state when the input is removed. Understanding whether a memory device “springs back” or “holds” is fundamental in sequential logic design, timing analysis, and state-machine behavior.

Given Data / Assumptions:

• We are dealing with bistable memory elements (SR latch, D latch, JK flip-flop, D flip-flop).
• Inputs that set or reset the device are momentary or synchronous.
• Once inputs are removed, the element is left undriven except for its feedback network and clocking scheme.

Concept / Approach:
Bistable circuits have two stable states maintained by positive feedback. The defining property of a memory element is that, after being forced into a state, it retains that state when the stimulus is removed, provided power is maintained and there is no asynchronous clear/preset event. They do not “revert” unless specifically designed with auto-clear or unless leakage/noise forces a change (which proper design avoids).

Step-by-Step Solution:

Verification / Alternative check:
Examine an SR latch built from cross-coupled NAND gates. After asserting S to set Q = 1, returning S to inactive leaves Q = 1 because the feedback sustains the condition. Similar behavior appears in clocked flip-flops between edges.

Why Other Options Are Wrong:
“Correct” contradicts the core property of memory retention. “Applies only to analog memories” is irrelevant; we are discussing digital bistables. “Depends solely on power-supply ripple” confuses noise susceptibility with fundamental operation.

Common Pitfalls:
Assuming inputs must be continuously driven to hold a state; misinterpreting metastability or power-on defaults as “reversion.”

Final Answer:
Incorrect