D Flip-flop

Purpose

Implement edge-triggered flip-flop

Library

Control / Logical

Description

../../_images/dflipflop.svg

The D flip-flop sets its output \(Q\) to the value of its input \(D\) when an edge on the clock input is detected. The behavior is shown in the following truth table:

D

Clk

Q

/Q

0

0

No change

No change

0

1

No change

No change

1

0

No change

No change

1

1

No change

No change

0

Triggering edge

0

1

1

Triggering edge

1

0

The input \(D\) is latched, i.e. when a triggering edge in the clock signal is detected the value of \(D\) from the previous simulation step is used to set the output. In other words, \(D\) must be stable for at least one simulation step before the flip-flop is triggered by the clock signal.

Parameters

Trigger edge

The direction of the edge on which the \(D\) input is read.

Initial state

The state of the flip-flop at simulation start.

Probe Signals

D

The input signal \(D\).

Clk

The clock input signal.

Q

The output signals \(Q\).

/Q

The output signals \(/Q\).