• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Digital system counters and karnaugh maps

Not open for further replies.

schmitt trigger

Well-Known Member
You mean 2-->9-->0-->7-->repeat
meaning in binary, an output of 0010, 1001, 0000, 0111, repeat?
And skip all other output codes?


Well-Known Member
Most Helpful Member
You mean 2-->9-->0-->7-->repeat
If this is ture:

You need 4 DFFs and some logic. (DFF is a data flip flop)
The logic look at the output of the FF and inputs a different number into the input of the FFs.
Logic: if 2 than 9, if 9 then 0, if 0 then 7, if 7 then 2.
>>only problem is that counter sometimes will not start up or gets locked and will not count.
Logic2: I would do it this way.
if 2 than 9, if 9 then 0, if 0 then 7, if (none of the above) then 2.
The improvement is that if the counter powered up with a 5 and the logic did not know what to do it might latch up.
Also if you are only looking for 2 or 9 or 0 then you are only looking for 3 states not 4. Might take less parts.
Not open for further replies.

Latest threads

EE World Online Articles