Finite-State Machines

Question 1

Define: Mealy-type FSM

Answer 1

Finite state machine whose output values are determined both by its current state and the current inputs.
->Action is performed depending on states and transitions.

Question 2

Define: Mooree-type FSM

Answer 2

Finite state machine whose output values are determined only by its current state.
->Action is performed when entering a state.

Question 3

Formal definition of FSM:

6-tuple

Answer 3

S: set of states
I: set of Boolean inputs
O: set of Boolean outputs
F: next-state (transition) function (A: S x I -> S)
A: entry action function (A: S -> O)
S0: initial state

Question 4

Formal definition of FSMD:
What does the FSMD stand for?
7-tuple

Answer 4

FSM with Datapath Model
V: is a set of passed on variables

• > Its passed/changed on by F (exit) (S x I x V -> S)
• > Its changed by A (entry) (S -> O + V)

Question 5

Define: Synchonous FSM

Answer 5

• FSM is time-triggered

- ->Transitions are performed at fixed period

Question 6

Define: Asynchonous FSM

Answer 6

• FSM is event-triggered

- ->Transitions are performed at certain conditions/Events

Question 7

How is the sampling rate of a synchronous FSM limited?

Answer 7

Period of FSM must be smaller than MEST

MEST: Minimum Event Seperation Time
–>smallest time between any two input events

Question 8

What are Advantages of an FSM

Answer 8

• Useful in all development phases
• Allow simulation of modeled behaviour
• Allow automatic code-generation (Not optimized)
• Test cases and robustnes