SR Flip-flop

Purpose

Implement set-reset flip-flop

Library

Control / Logical

Description

../../_images/srflipflop.svg

The SR Flip-flop behaves like a pair of cross-coupled NOR logic gates. The output values correspond to the following truth table:

S

R

Q

/Q

0

0

No change

No change

0

1

0

1

1

0

1

0

1

1

Restricted (0)

Restricted (0)

The combination \(S = R = 1\) is restricted because both outputs will be set to \(0\), violating the condition \(Q = \mathbf{not}(/Q)\). If both inputs change from \(1\) to \(0\) in the same simulation step, \(Q\) will be set to \(0\) and \(/Q\) to \(1\).

Parameters

Initial state

The state of the flip-flop at simulation start.

Probe Signals

S

The input signal \(S\).

R

The input signal \(R\).

Q

The output signals \(Q\).

/Q

The output signals \(/Q\).