4. A control mechanism for a vending machine accepts 10p and 5p pieces. It dispenses a chocolate bar when 20p is deposited; the mechanism does not give change if 25p is deposited. Design an asynchronous FSM that implements the mechanismuse as few states as possible. Use Partition Minimisation and State Merge to ensure your design is as small as possible. [30] 5. How many single stuck-at faults are there in the circuit F = A.B + C? How many double stuck-at faults? How many triple stuck at faults? Use the path sensitisation technique to derive a minimal set of tests for all the single stuck-at faults in the circuit. [10] 6. Draw a Dadda tree that adds seven 5-bit numbers. You should refer to the values in the table below when preparing your answer. R(h) 28 42 (lo) 2 13 8 24 361 10 11 5131 12 19 13 Dadda tree heights and operand numbers ---- 63 94 141 211 16 3 [20] 4. A control mechanism for a vending machine accepts 10p and 5p pieces. It dispenses a chocolate bar when 20p is deposited; the mechanism does not give change if 25p is deposited. Design an asynchronous FSM that implements the mechanismuse as few states as possible. Use Partition Minimisation and State Merge to ensure your design is as small as possible. [30] 5. How many single stuck-at faults are there in the circuit F = A.B + C? How many double stuck-at faults? How many triple stuck at faults? Use the path sensitisation technique to derive a minimal set of tests for all the single stuck-at faults in the circuit. [10] 6. Draw a Dadda tree that adds seven 5-bit numbers. You should refer to the values in the table below when preparing your answer. R(h) 28 42 (lo) 2 13 8 24 361 10 11 5131 12 19 13 Dadda tree heights and operand numbers ---- 63 94 141 211 16 3 [20]