0
\$\begingroup\$

I have a few questions to ask about electronics.I am studying computer science in my first year and I have a logic design course where the professor is kind of old let's say and he expects us to study like #### for his course, and he only offers us inconceivable pdf's with things he will never explain to us so we are pretty much on our own.Now we have a project, and mine is to design and implement a Moore machine that has an input L and an output Z.The output takes (and keeps it forever, no matter the input) the value 1 whether 2 values of 0 and two values of 1 have been detected as input(i.e 0010001 will give the output 1, as well as 0111111110 or any other combination you might think).I must use D flip-flops and NAND gates only.So I have drawn this state diagram and this table(CS stands for current state and FS stands for future state, but I do not know what to do further.I know that I must draw 8 Kmaps I think but I am not sure and I have to use 3/4 flip flops.Any effort would be greatly appreciated :Denter image description here

EDIT

ok so after some more research i finally managed to draw the Kmaps and i was able to extract the functions, and this is the circuit I've designed using logisim, but i don't think it is doing what i want it to do, or maybe the circuit is good but i don't understand the mechanics behind the simulator or the way the flip-flops and the clock function.Any suggestions of what may be wrong? This is the link to the .circ file that you can open with logisim

http://www.filedropper.com/beta1

\$\endgroup\$
  • \$\begingroup\$ Remember that you can build OR, NOR, NOT, AND, and NAND by combining NANDs. \$\endgroup\$ – JimmyB Dec 1 '14 at 11:10
  • \$\begingroup\$ Maybe try to design a circuit which will detect and store the first 1 (or 0) bit it sees. Then combine some of those elements to the complete circuit. \$\endgroup\$ – JimmyB Dec 1 '14 at 11:12
3
\$\begingroup\$

Being kind of old myself, I expect you to study like #### too. :D

One question may help clarify the circuit you need : how does it distinguish between 2 successive states that are the same? Or alternatively : Is there a separate clock signal, not mentioned above? If so, the basic pattern of the circuit may become clear.

Ask yourself :
how many states do you have?
how many bits are required to implement all these states?

You have already given each state a unique number : it will help to write those numbers out in binary as part of each state table.

Then treat each bit of that number separately : first create a Karnaugh map for the next state for bit 0. What are the input variables for that KMap?

\$\endgroup\$
  • \$\begingroup\$ can you look over my circuit and give me some feedback? \$\endgroup\$ – andrei985 Dec 8 '14 at 15:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.