the one that you did is different way of wiring and I didn't know that. it is quite neat and clear.

 

Hello nadia23

Yes I check your circuit named Assign1part2.cdl, apparently works.
but not fully in CEDAR but in Proteus ISIS.
-Removing all unused devices in your design-

To adjust (Set time) you can use the inputs R and S on each Flip-Flop.
But in this case more gates will be required to select: Running OR Adjusting time.
Example: Adjust to 1:50.
Stop the timer.
Adjust the S and R buttons according to the above numbers.
See:
S = 0 give Us Q = 1, but If R= 1.
R = 0 give Us Q = 0, but If S= 1.

The result should be:
Flip-Flip's for Seconds (Units) Q’s: 0 0 0 0 Bin, 0 Dec.
Flip-Flip's for Seconds (Tens) Q’s: 0 1 0 1 Bin, 5 Dec
Flip-Flip's for Minutes (units) Q’s: 0 0 0 1 Bin, 1 Dec
According to the numbers above.
Select: Up or Dn as required.
Change to Run.

! So many components !, the simulator probably can not handle.
Have You the specifications of this simulator CEDAR ?

 

Hello nadia23

I'm sorry, reading your scheme is very hard for my eyes.
The CEDAR placed wires like BUS, a wire over another. Of course, we can rearrange those wires but the task is more difficult to do.
Someone who tries to read your circuit will surely be very difficult to understand.
Try to improve the way of wiring your designs. otherwise it is difficult to help.

Open the PDF document I am attaching you.
Notice how could be reset to 0 when counting up.
And how could be reset to 9 when counting down.
Fortunately in your simulator also brings three states NOT Gates.

Be aware that this circuit is only for units of seconds.
The tens of seconds could be very similar.
Same for counter units of minutes.

You are developing a counter clock style.
When seconds reach 59, you must reset to 0 at the next clock pulse.
And the counter for units of minutes must count +1.

 

Hi Mrcarlos
Thanks for your help so far, I submitted my assignment today, hope to pass

I will try to make the counting up and down circuits the way u suggested