Hello, I've been asked to create a countdown that starts from 9 and counts down to 0.
but, I'm struggling with setting the register value to a specific number. Whenever I need to reset the register, it defaults to 0.

Below is my circuit:


Thank you.

 

Hi H800.
Welcome to AAC,
Which type of counter IC device are you using?
E

 

Hi E,
I have no idea, I've just been asked to use Cedar Logic Simulation to create a counter from 9 to 0 and 5 to 0, along with a reset button, using registers and logic gates.

I'm just not sure how I'm supposed to set the register value to another, like jumping from 1 to 9 when pressing the reset button.

 

Hi H,
I don't use the Cedar simulator.
You can see on the left side of the counter IC drawing there are 4 pin lines, these are used to set the output of the counter from a number from '0' to' 9'.
The other pins along the top are usually a parallel load pin which is used to load the count value on the left pins into the counter.
Just using the Reset pin line will default the count to '0'.

E

 

hi H,
Check out this link, it covers the Cedar Sim.
E
https://www.youtube.com/results?search_query=cedar+logic+siumation+of+bcd+counter

 

Got it working! Thank you!

 

Hi H,
Well done.
Please post your circuit, it will help other students.
E

 

Sure thing!

This is how I did the countdown from 9 to 0:

 

Your generic counter has four inputs. Set these input pins to the BCD value that you want to preset.
I would assume that the L input means LOAD. Try sending a high pulse into L to load the register.

Make sure that the R input (assuming that this is RESET) is set to the inactive state. Don't leave it not connected.

 

Sure thing!

This is how I did the countdown from 9 to 0:
View attachment 320906

That may work in a particular simulator, but it may not with a real part due to glitches and timing constraints.