# 4 bit parity counter

Discussion in 'Homework Help' started by Zuryuk, Apr 7, 2015.

1. ### Zuryuk Thread Starter New Member

Apr 7, 2015
3
0
Hi I am little stuck on coursework I could use help or direction to other learning sites to read about this kind of project. I chose to use JK-flip flops and planned following structure diagram: https://i.imgur.com/9hNAMgu.png. I made it quickly on computer but idea is that it keeps looping odds or evens depending on input and when input changes it round up to closes odd/even number and continues the other loop.

I also did transition table on excel https://i.imgur.com/30Xg209.png I know next I'm supposed to make Karnaugh's map, but I can't get even started because we have never discussed 4 bit counters during lectures, maximum I have received teaching for is 2 bit counter. I saw similar(ish) kinda build in here http://www.doc.ic.ac.uk/~dfg/hardware/HardwareLecture08.pdf using D-type flip flops, but it still only uses 3 bits. Thanks in advance. I hope you can help me.

2. ### WBahn Moderator

Mar 31, 2012
17,447
4,699
What on earth is a "parity counter"?

What does it mean to "keep looping odds or evens on input"?

Please describe, exactly, the specifications for your assignment. The first part in solving a problem is being able to clearly express what the problem is.

3. ### WBahn Moderator

Mar 31, 2012
17,447
4,699
I took a look at your diagram and I think I know what you are supposed to do, but what happened to values 12, 13, 14, and 15?

4. ### Zuryuk Thread Starter New Member

Apr 7, 2015
3
0
Parity indicates if number is odd or even. Assigment freely translates to : "Plan a counter, that can be made to count even numbers from zero to ten or odd numbers from one to eleven. Evens if INPUT = 0 odss if INPUT = 1."
Sorry for bad wording earlier this should also answer question what happens with 12,13,14 and 15; for some reason I forgot to mention that earlier.

5. ### WBahn Moderator

Mar 31, 2012
17,447
4,699
Okay, so I agree that your state diagrams look good. It is pretty clear to understand them, but perhaps a better way would be to show them as two concentric rings, each with six states. You could put each state on one of the radials of the clock but have the odds in closer than the evens. Your final state diagram should also document all of the unused states and transitions.

Assuming your transition table is correct (the form looks fine, I didn't look at the contents) you have eight signals you need to do the logic for and each one has five inputs. So you need to look at how you do 5-input K-maps. They aren't hard, but it isn't something that most people would figure out on their own.

6. ### Zuryuk Thread Starter New Member

Apr 7, 2015
3
0
Yeah state diagrams are little better on paper. I'll also mark the unused states in next version. I'll definitely also look to 5-input K-maps. Thanks for the answers I think I can get on with this project now.

7. ### WBahn Moderator

Mar 31, 2012
17,447
4,699
Good. I think you are doing fine. Follow-up if you run into any glitches.

8. ### RRITESH KAKKAR Senior Member

Jun 29, 2010
2,831
89
Hello,
may i know what are you doing of it?