Flip-flop transformation: if a single inverter is inserted such that one input of an SR latch receives D and the other receives the complement of D, what type of flip-flop results?

Introduction / Context:
Flip-flops can be transformed by constraining their inputs. An SR latch/flip-flop with both inputs driven by complementary versions of the same signal behaves as a D (data) flip-flop, capturing the single input value.

Given Data / Assumptions:

• Base device: SR latch/flip-flop.
• Inputs are forced to be complements: S = D and R = not D (via an inverter).
• Assume proper edge/level control to avoid illegal SR=1,1 state.

Concept / Approach:
With S = D and R = not D, only one of S or R can be asserted at a time. When D = 1, set is asserted and the device stores 1; when D = 0, reset is asserted and it stores 0. This exactly matches D flip-flop semantics: on the active control (clock or enable), Q_next = D.

Step-by-Step Solution:

Verification / Alternative check:
Truth behavior of a D flip-flop is Q_next = D at the sampling event. The constrained SR realization reproduces this, confirming equivalence.

Why Other Options Are Wrong:

Common Pitfalls:
Driving S and R high simultaneously (forbidden); omitting proper gating/clocking when building edge-triggered D FF from level-sensitive latches.

Final Answer:
D flip-flop