I'm currently got a course work required design a 7 segment display by
using a JK flip-flop to build a numbering countdown minimun with 1
I'd like to know is, what is the way or how i do design the circuit,
now i no any idea to design it..
i don't have any idea right now, so please help me please...
(sorry for my parlance or using sentence wrongly.. i also very
hardworking to learn English )
Are you really going to school some place where there are neither
instructors nor teaching assistants who talk to students? That's the
preferred route -- if for no other reason then if 1/4 the class asks the
same question (and the guy's not a dip) he'll realize he's got to go
over the material again.
This is a basic exercise in digital logic, although a 7-segment display
is a bit much. If you truly are tasked with using seven flip-flops, you
want to make a map of the ten allowable states of the display, with the
J and K inputs necessary to each flip-flop to generate the next step in
the count down. With four bits this is easily done by exhaustively
listing all 16 possible states and their follow-ons, then making a
Karnaugh map, but with seven it would be a pain. There's a technique
that basically works like a Karnaugh map in tabular form, but I can't
remember it, and you'd still need 128 entries just to get 10 valid states.
You _could_ look at the seven segments to see if there are just four or
five unique ones, then use those for your Karnaugh map -- this might be
how I would proceed, assuming I couldn't just use a PIC and some software.
If you're just supposed to use J-K flip-flops _somehow_ then I suggest
you make a plain-jane 4-bit down counter, and a bunch of NAND gates to
map the bits to the segments -- I suspect this will require less logic,
but what do I know?
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