Description
Step 1: State the inputs and outputs of the state registers.
Inputs: N2, N1, N0, clock, reset
Outputs: S2, S1, S0
Step 2: State the inputs and outputs of the combinational block.
Inputs: x, S2, S1, S0
Outputs: N2, N1,N0, y1, y0
Step 3: Write each output (including next state bits) as a function of the inputs.
N 2 =S2S1’S0’x + S2’S1S0x
N 1 =S2’S1’S0x + S2’S1S0’x
N 0 = S2’x’ + S2S1’S0’x’ + S2’S1S0’x
Y 1 = S2’S1S0x’ + S2S1’S0’x’
Y 0 = S2’S1S0’x’ + S2S1’S0’x’
Step 4: Draw the truth table for the combinational circuit.
| # | S 2 | S 1 | S 0 | X | N
2 |
N
1 |
N
0 |
Y 1 | Y 0 |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 |
| 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 2 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 |
| 3 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 0 |
| 4 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
| 5 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 |
| 6 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 0 |
| 7 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 8 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |
| 9 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 |
| 10 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
Student Names:H. Kübra Eryılmaz/ Yağmur Ceren Dardağan
Student IDs:2014400186/ 2014400063
Group ID: 4
Experiment 4 (Analysis of a Sequential Circuit)
| 11 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
| 12 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 13 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 14 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| 15 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
Step 5: Draw the finite state machine by using the truth table.
# of Unreachable States: 3 (111) (110)(101)
Step 7: Briefly explain the relation between the input and the output.
Explanation: It counts 1’s between 0’s. If the 1’s between 0’s is 1 -> output 01; If the 1’s between 0’s is 2 -> output 10; If the 1’s between 0’s is more then or equal to 3 -> output 11. Else the output is 00
