7-segment Numeric display

1
7-segment Numeric display
a
b
c
d
e
f
g
2
Karnaugh (K) Maps
Recall To represent decimal values 0-9 requires
4 binary digits
Variables ABCD each represent one binary digit
electrically
Four wires means 16 possible values
Four possible values for two binary digits
Each entry is one possible combination of
ABCD e.g. 6 is ABCD0110
16 possible values for four binary digits (we
only use 0 through 9 for a digital watch)
3
The F-segment
This segment
Goal Determine for which values the segment is
lit, and for which it isnt
is Dont Care These dont matter, since display
will never have this value
4
The F-segments code
f-segment
CD
00
01
11
10
1
1
1
0
00
1
1
1
1
01
AB




11
1
1


10
On for every number except 2
5
The F-segment
CD
00
01
11
10
AB
1
1
1
0
00
1
1
1
1
01




11
1
1


10
6
Wire it up!