# Flip Flop counter design

#### EYT1

Joined Apr 7, 2020
84
Hi,

How do I design the synchronous number that periodically counts (0-6-4-2) with JK FF using?

#### WBahn

Joined Mar 31, 2012
29,493
MOD NOTE: Moved to Homework Help.

#### WBahn

Joined Mar 31, 2012
29,493
How many different states do you have?

How many FF do you need to encode those states?

You need to show YOUR best attempt to solve the problem, not just ask others how to do it.

#### MrChips

Joined Oct 2, 2009
29,814
Note that there is trick in this assignment.

How many different states do you have?
How many FF do you need to encode those states?

#### Papabravo

Joined Feb 24, 2006
20,598
Why are all the J & K inputs unconnected?
Why do you need 4 FF's to show 4 different values?
How do you make a JK FF always contain a 0?

That should get you started

#### MrChips

Joined Oct 2, 2009
29,814
How many different states do you have?

0000 - 0110 - 0100 - 0010
0 6 4 2
I must be blind. I can only see four states.

#### EYT1

Joined Apr 7, 2020
84
I must be blind. I can only see four states.
[/ALINTI]
I'm sorry, I fixed it.
000-110-100-010

#### MrChips

Joined Oct 2, 2009
29,814

#### EYT1

Joined Apr 7, 2020
84

#### MrChips

Joined Oct 2, 2009
29,814
I'm sorry, I don't quite understand.
State 1 is 0000
State 2 is 0110
State 3 is 0100
State 4 is 0010

There are only four states in this machine.

#### EYT1

Joined Apr 7, 2020
84
State 1 is 0000
State 2 is 0110
State 3 is 0100
State 4 is 0010

There are only four states in this machine.
I've identified those situations, what should I do next?

#### MrChips

Joined Oct 2, 2009
29,814
I've identified those situations, what should I do next?
How many flip-flops do you need to represent four states?

#### EYT1

Joined Apr 7, 2020
84
How many flip-flops do you need to represent four states?
2 ^ 3 = 8 jk FF need 3

Last edited:

#### MrChips

Joined Oct 2, 2009
29,814
How many states does one flip-flop have?

#### EYT1

Joined Apr 7, 2020
84

#### MrChips

Joined Oct 2, 2009
29,814
00
01
10
11
are four states in total, not 2.

How many states does one flip-flip have?

If I have an 8-bit register, how many unique 8-bit patterns can I show?

#### EYT1

Joined Apr 7, 2020
84
00
01
10
11
are four states in total, not 2.

How many states does one flip-flip have?

If I have an 8-bit register, how many unique 8-bit patterns can I show?
Yes one flip-flop of 2 bit 4 state

8-bit pattern of N bits 2^N formule. Am i wrong?

#### MrChips

Joined Oct 2, 2009
29,814
N is the number of flip-flops. Fill in the table below:

N # of states
1
2
3
4
5
6
7
8

#### EYT1

Joined Apr 7, 2020
84
N is the number of flip-flops. Fill in the table below:

N # of states
1
2
3
4
5
6
7
8
N # of states
1 0 0 0 0
2 0 0 1 1
3 0 1 0 2
4 0 1 1 3
5 1 0 0 4
6 1 0 1 5
7 1 1 0 6
8 1 1 1 7

#### MrChips

Joined Oct 2, 2009
29,814
Let us try a different approach.

I have a coin. I flip it into the air once and it lands on the floor.
How many different ways can it land on the floor?