Simulator Reference: JK Flip Flop

In this topic:

Netlist entry
Axxxx j k clk set reset out nout model_name

Connection details

Name

Description

Flow

Type

j

J input

in

d

k

K input

in

d

clk

Clock

in

d

set

Asynchronous set

in

d

reset

Asynchronous reset

in

d

out

Data output

out

d

nout

Inverted data output

out

d

Model format
.MODEL model_name d_jkff parameters

Model parameters

Name

Description

Type

Default

Limits

clk_delay

Delay from clk

real

1nS

1e-12 ???MATH???- \infty???MATH???

set_delay

Delay from set

real

1nS

1e-12 ???MATH???0 - \infty???MATH???

reset_delay

Delay from reset

real

1nS

1e-12 ???MATH???0 - \infty???MATH???

ic

Output initial state

integer

0

???MATH???0 - 2???MATH???

rise_delay

Rise delay

real

1nS

1e-12 ???MATH???0 - \infty???MATH???

fall_delay

Fall delay

real

1nS

1e-12 ???MATH???0 - \infty???MATH???

jk_load

J,k load values (F)

real

1pF

none

clk_load

Clk load value (F)

real

1pF

none

set_load

Set load value (F)

real

1pF

none

reset_load

Reset load value (F)

real

1pF

none

family

Logic family

string

UNIV

none

in_family

Input logic family

string

UNIV

none

out_family

Output logic family

string

UNIV

none

out_res

Digital output resistance

real

100

???MATH???0 - \infty???MATH???

out_res_pos

Digital output res. pos. slope

real

out_res

???MATH???0 - \infty???MATH???

out_res_neg

Digital output res. neg. slope

out_res

???MATH???0 - \infty???MATH???

min_sink

Minimum sink current

real

-0.001

none

max_source

Maximum source current

real

0.001

none

sink_current

Input sink current

real

0

none

source_current

Input source current

real

0

none

Device Operation
The following circuit and graph illustrate the operation of this device:

The following table describes the operation of the device when both inputs are at known states: The output can only change on a positive edge of the clock.

J input

K input

Output

0

0

No change

0

1

0

1

0

1

1

1

toggle

When either input is UNKNOWN, the situation is more complicated. There are some circumstances when a known state can be clocked to the output even if one of the inputs is unknown. The following table describes the operation for all possible input states. X means UNKNOWN.

J input

K input

old output

new output

0

0

0

0

0

0

1

1

0

0

X

X

0

1

0

0

0

1

1

0

0

1

X

0

0

X

0

0

0

X

1

X

0

X

X

X

1

0

0

1

1

0

1

1

1

0

X

1

1

1

0

1

1

1

1

0

1

1

X

X

1

X

0

1

1

X

1

X

1

X

X

X

X

0

0

X

X

0

1

1

X

0

X

X

X

1

0

X

X

1

1'

0

X

1

X

X

X

X

0

X

X

X

1

X

X

X

X

X

◄ Inverter
 
Arbitrary Logic Block ▶