# How can I connect these two circuits using a D flip-flop?

#### dl324

Joined Mar 30, 2015
14,346
Just so we're on the same page, the first counter counts from 0-5 and the second counts from 0-9, right?
Good question. By first counter, I mean the Least Significant Digit (LSD). Physically, you could consider the 10's digit to be the first, but logically, I consider the LSD first.

Since R1 is responsible for resetting the counter, it would make sense that this signal is used to trigger the 0-5 counter to increment
OK. What would happen if you connected R1 to the clock input of the MSD counter?

#### pinkoryx

Joined Dec 11, 2017
47
IT (almost) WORKED!!!!!!
it displayed 10-19
then skipped 20-29
then displayed 50-59
and skipped 0-9

#### dl324

Joined Mar 30, 2015
14,346
IT (almost) WORKED!!!!!!
it displayed 10-19
then skipped 20-29
then displayed 50-59
and skipped 0-9
That's not what I'd expect it to do. I'd expect the count to increment from 00 to 09, quickly change to 19, and then count from 10 to 19 (then quickly change to 29).

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#### pinkoryx

Joined Dec 11, 2017
47
So sorry, I'm mistaken!
it displays 0-9, changes to 19, then displays 20-29, changes to 39, displays 40--49, changes to 59 and repeats

#### dl324

Joined Mar 30, 2015
14,346
it displays 0-9, changes to 19, then displays 20-29, changes to 39, displays 40--49, changes to 59 and repeats
That doesn't make sense.

Take a closer look at what happens when the 1's (first) counter gets to 9. Slow the clock down enough for you to see all of the transitions separately.

#### pinkoryx

Joined Dec 11, 2017
47
Yup! I did just that. When the ones counter gets to 9, the tens counter counts up before the ones counter resets
so it goes like this: 00,01,02,03,04,05,06,07,08,09,19, then 20.. etc

#### dl324

Joined Mar 30, 2015
14,346
so it goes like this: 00,01,02,03,04,05,06,07,08,09,19, then 20.. etc
From 09, it should go to 19 then 10, 11, 12, ..., 19, 29, 20, 21, etc.

#### pinkoryx

Joined Dec 11, 2017
47
I don't know what's up with it, but it changes the way it counts every time i open launch cedar, now it counts 50-59, skips 0-9, then counts 10,11,12,13.. etc (so now it basically displays the proper output only for odd tens digits)

#### dl324

Joined Mar 30, 2015
14,346
I don't know what's up with it, but it changes the way it counts every time i open launch cedar, now it counts 50-59, skips 0-9, then counts 10,11,12,13.. etc (so now it basically displays the proper output only for odd tens digits)
Use the scope feature to troubleshoot the second counter. Put "To" named links on the 4 outputs and one on the clock. That might give you some clues.

#### pinkoryx

Joined Dec 11, 2017
47
Use the scope feature to troubleshoot the second counter. Put "To" named links on the 4 outputs and one on the clock. That might give you some clues.

I clicked on view > oscope and the window popped up but it was empty, how do I load the counter to it?

#### dl324

Joined Mar 30, 2015
14,346
I clicked on view > oscope and the window popped up but it was empty, how do I load the counter to it?
Did you add the "To" components to the counter outputs and clock?

The "To" components will show up in a pick list that you can add for display.

#### pinkoryx

Joined Dec 11, 2017
47
hmm.. I don't think we're on the same page, this is what pops up on my version of cedar:

#### dl324

Joined Mar 30, 2015
14,346
hmm.. I don't think we're on the same page, this is what pops up on my version of cedar:
Did you click on the arrow for the pull down menu?

#### WBahn

Joined Mar 31, 2012
26,398
The thing is I am asked to do this assignment (and it's worth a lot of my final grade) and have 0 knowledge about D flip flops, what they do, how they work, registers (and their connections), which is why I'm here. I have done research on the internet and it was of no help. Also,I am not given enough information on these topics in my curriculum to begin with which is why i'm lost (I didn't even know the thing I'm working on is called a mod 60 counter until you mentioned it)

sorry if my circuit looks like a headache i'm a total newbie who just needs some guidance
What class/course is this for?

Nowhere in this course or any of its prerequisite courses have they covered D flip flops? If that is truly the case, then get out of that program and, probably, away from that school entirely. You will do nothing except spend a lot of time and money getting a degree that is worthless.

The far more likely scenario is that this WAS covered and, for whatever reason, you didn't learn it when it was.

You say that you've done research on the internet yet still have no idea what a D flip flop is or how to work with it. I just did a Google search for "D flip flop" and got many good hits on tutorials about D flip flops. If you have gone through several of these and still have no idea what a D flip flop is, then you likely do not have the foundational knowledge to be taking this course in the first place and you need to take however many steps back are needed and get that foundation in place. Without it, you are just going to be digging yourself deeper and deeper into a hole that will only get increasingly more difficult to climb out of.

#### pinkoryx

Joined Dec 11, 2017
47
It's a logic design course. yup you said it, I don't have the prerequisites I need to learn about D flipflops. I, too, found tutorials on youtube but they were of no help to me

#### WBahn

Joined Mar 31, 2012
26,398
It's a logic design course. yup you said it, I don't have the prerequisites I need to learn about D flipflops. I, too, found tutorials on youtube but they were of no help to me
Well, there's an old saying that applies. When you find yourself needing to get out of a deep hole, the first step is to stop digging.

What you are doing with this exercise is a case in point. You seem to be getting someone to spoon feed you a solution one piece at a time. At the end of the day, even if you end up with something that gets you a grade, there is little indication that YOU will have learned much of anything from it. Which only means that you will move on to the next course even less prepared for it than you were for this one. You are building a house of cards that is already starting to crumble around you. It's only going to get worse as long as you keep using the same shovel that has gotten you to where you currently are.

#### pinkoryx

Joined Dec 11, 2017
47
I totally agree!! I do not want anyone to spoon feed me and would much rather get deducted than score a full mark that I don't deserve.

#### dl324

Joined Mar 30, 2015
14,346
I did and nothing showed up
Did you add some of the "To" devices and connect them to the nets you want to view?

#### dl324

Joined Mar 30, 2015
14,346
I do not want anyone to spoon feed me and would much rather get deducted than score a full mark that I don't deserve.
Don't worry, I'm not going to just give you the answer.

I'll try to teach you to figure out what's going on so you'll be able to troubleshoot other problems.

What is it that you don't understand about D flip flops?