"digital systems"1 7-segment numeric display b a d g e c f
DESCRIPTION
"Digital Systems"3 The F-segment #### 11## CD AB This segment Goal: Determine for which values the segment is lit, and for which it isn’t # is Don’t Care These don’t matter, since display will never have this valueTRANSCRIPT
"Digital Systems" 1
7-segment Numeric display
b
a
d
ge
c
f
"Digital Systems" 2
Karnaugh (K) Maps
0 1 3 2
4 5 7 6
12 13 15 14
8 9 11 10
00
01
11
10
00 01 11 10
CD
AB
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
16 possible values for four binary digits (we only use 0 through 9 for a digital watch)
Each entry is one possible combination of ABCDe.g. 6 is ABCD=0110
"Digital Systems" 3
The F-segment
1 1 1 0
1 1 1 1
# # # #
1 1 # #
00
01
11
10
00 01 11 10
CD
AB
This segmentGoal:
Determine for which values the segment is lit, and for which it isn’t
# is Don’t CareThese don’t matter, since display will never have this value
"Digital Systems" 4
The F-segments coden A B C D f(A,B,C,D)
0 0 0 0 0 1 1 0 0 0 1 1 2 0 0 1 0 0 3 0 0 1 1 1 4 0 1 0 0 1 5 0 1 0 1 1 6 0 1 1 0 1 7 0 1 1 1 1 8 1 0 0 0 1 9 1 0 0 1 1
1
1 1 1 0
1 1 1 1
# # # #
1 1 # #
00
01
11
10
00 01 11 10CD
AB
f-segment
On for every number except 2
"Digital Systems" 5
The F-segment
1 1 1 0
1 1 1 1
# # # #
1 1 # #
00
01
11
10
00 01 11 10
CD
AB
BorCnotorDDCBAf )(),,,(
"Digital Systems" 6
Wire it up!
BorCnotorDDCBAf )(),,,(
ABCD