0110
0010
1010
1110
1111
1011
1001
1101
THere it is. I need a state machine using JK flip flops that will count
through that sequence.
is it even possible?
Ive been busting my brain for a long time and CANNOT do it.
sam fakhreddine
Yes it is possible, I did something similar as a University project
several years ago but with a more complicated sequence. Your
application sounds like a similar Uni project so I will reply as if it
was so, if not please clarify your application further. You have a
sequence of 8 states of 4-bit numbers, this is called modulo-8. 4-bit
binary numers naturally repeat after 2^4=16 sequences i.e. 0000,
0001...1110, 1111, then loop back to 0000 i.e. modulo-16. Four J-K
flip-flops will generate this for you, look up the circuit in a search
engine or digital book. You need to reset the FF's after 8 states to
change it to modulo-8, you do this by generating a RESET* when the
output reaches 0111 (dec 7), this can be achieved by using 1 NOT and 2
AND gates feeding into the RST* input of each FF. (If it is active low,
use another NOT gate to invert), 0000, 0001...0110, 0111 then loop back
to 0000, now you have a modulo-8 state machine. The next step is to put
your target sequence into a state table and use Karnaugh maps to
generate the equations for AND and OR gates. Find more on Karnaugh maps
in a book or in a SE, it would take too long to explain here. Minimise
the equations and use the appropriate AND, OR, NOT gates etc. to
generate your desired sequence. It would be worth your while generating
the circuit in a simulator before attempting to build it, it will save
at lot of headache.
Hope this helps.
Alan.
www.electronic-eng.com