AQA A level Computer Science
Teaching and Learning Resources
Chapter 18 – Finite state machines
TASK QUESTIONS (WITH ANSWERS)
1
2
Look at the diagram below. Which of these are acceptable:
a)
caabb
NO
b)
bac
NO
c)
aaabbccc
YES
d)
abc
YES
e)
aabbca
NO
Draw a state transition diagram and table that evaluates whether a sequence of bits has an
even number of zeros.
Suggested drawing:
AQA A level Computer Science
© Hodder & Stoughton Limited 2015
AQA A level Computer Science
Teaching and Learning Resources
A level only
3
What is a Mealy machine?
A Mealy Machine is a finite state machine with outputs.
4
Draw a state transition diagram from the following table:
Input
Current state
Output
Next state
1
S0
A
S1
2
3
S2
S1
B
C
S1
S3
4
S3
D
S2
Suggested drawing:
5
Draw a state transition diagram that will carry out a bitwise XOR operation.
Suggested drawing:
AQA A level Computer Science
© Hodder & Stoughton Limited 2015