Assignment 7 Solutions
A.34
Let
s
i
represent the Q output of state flip-flop
s
i
, and let
D
i
represent the D input to state flip-flop
s
i
.
For the decoder, X is the least significant bit and
s
2
is the most significant bit.
Present State
Next State / Output
X = 0
X = 1
s
2
s
1
s
0
D
2
D
1
D
0
/ Z
D
2
D
1
D
0
/ Z
0 0 0
0 0 1 / 0
0 1 0 / 0
0 0 1
0 1 1 / 0
1 0 0 / 0
0 1 0
1 0 0 / 0
0 1 1 / 0
0 1 1
0 0 0 / 0
0 0 0 / 0
1 0 0
0 0 0 / 1
0 0 0 / 1
Four-bit register that increments by 0, 1, 2, or 4.
