D Flip-Flop

Model a positive-edge-triggered enabled D flip-flop

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Libraries:
Simulink Extras / Flip Flops

Description

The D Flip-Flop block models a positive-edge-triggered enabled D flip-flop. The D Flip-Flop block has three inputs:

• D — data input

• CLK — clock signal

• !CLR — enable input signal

On the positive (rising) edge of the clock signal, if the block is enabled (!CLR is greater than zero), the output Q is the same as the input D. The truth table for the D Flip-Flop block follows.

Note

The D Flip-Flop block treats a nonzero input as true (1).

D	Q	!Q
1	1	0
0	0	1

If the block is not enabled on the rising edge of the clock signal, Q is reset to zero. When the clock signal is not rising, the block remains in the previous state.

Logic Signals as Boolean or Double Data Types

The Implement logic signals as boolean data (vs. double) configuration parameter setting affects the input and output data types of the D Flip-Flop block because the D Flip-Flop is a masked subsystem that uses the Logical Operator block. The Logical Operator block in the masked subsystem has the following parameter settings:

Block Parameter	Setting
Output data type	Inherit: Logical
Require all inputs and output to have the same data type	On

For more information about the Implement logic signals as boolean data (vs. double) configuration parameter, see Implement logic signals as Boolean data (vs. double).

Ports

Input

D — Data input signal

scalar | vector | matrix

Data input signal, specified as a scalar, vector, or matrix.

Dependencies

The data types that the D Flip-Flop block accepts for the input D depend on the setting of the Implement logic signals as boolean data (vs. double) model configuration parameter. If this parameter is on, D must have data type boolean; if this parameter is off, D can have data type boolean or double.

Data Types: double | Boolean

CLK — Clock signal

scalar | vector | matrix

Clock signal, specified as a scalar, vector, or matrix.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean | fixed point | enumerated | bus

!CLR — Enable input signal

scalar | vector | matrix

Enable input signal, specified as a scalar, vector, or matrix.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean | fixed point | enumerated | bus

Output

Q — Output signal Q

scalar | vector | matrix

Output signal Q, with the same dimensions and data type as the input D.

Data Types: double | Boolean

!Q — Output signal !Q

scalar | vector | matrix

Output signal !Q, with the same dimensions and data type as the input D.

Data Types: double | Boolean

Version History

Introduced in R2008b