A numeric keypad produces a 4-bit code as shown below. We want to design a logic circuit that converts each 4-bit code to a 7-segment code, where each segment is an LED. The LEDs are lit with a logical '0' (negative logic). The inputs are active high (or in positive logic).
Complete the truth table for each output (a, b, c, d, e, f, g). (4 pts) Provide the simplified expression for each output (a, b, c, d, e, f, g). Use Karnaugh maps for a, b, c, d, e and the Quine McCluskey algorithm for f, g. Note that it is safe to assume that the codes 1100 to 1111 will not be produced by the keypad.
a
X y z W
6
a
Value MZXX abcdefg
0:
1:
2:
3:
4:
5:
6:
7:
8:
9:
D:
0 0 0 0 0 0 0 1
0 0 1 0
0 0 1
0 1 0 0 0 1 0 1
0 1 1 0
0 1 1 1
1 0 0 0
6
7:
8:
9:
D:
1 0 0 1
0000100
1 0 1 0
1 0 1
1 1
0 0
1 1 0 1
1 1 1
1
1