The document presents a team project by students on finite state machines (FSMs), detailing their importance in digital systems for decision-making and control. It explains the structure of FSMs, including states, transitions, and outputs, using examples such as CPU instruction cycles and TV remote functionality. The document concludes with applications of FSMs in various fields like digital logic design and natural language processing.

2. MEET
Gohar Abbass
Muhammad Haris
Muhammad Bilal
Abdul Rehman
23021519-
116
23021519-084
23021519-092
23021519-147
Muhammad Bilal
TEAM
OUR
PRESENTED TO
Ms. Sehar Aftab
BSCS23(II-A-Mor)
TOPIC
FINITE STATE MACHINES

3. 1
Overview
2
3
Finite State Machines
Building Blocks/Types
4 State Diagram
5 Applications
Programmable Implementation of
Functions (PROM, PAL, PLA)
6

4. FINITESTATEMACHINES

5. FINITESTATEMACHINES
Timer State Next
State
0 R R
1 R G
0 G G
1 G Y
0 Y Y
1 Y R
t=0

6. FINITESTATEMACHINES
Timer State Next
State
Output
0 R(00) R (00)
1 R(00) G (01)
0 G(01) G (01)
1 G(01) Y (10)
0 Y(10) Y (10)
1 Y(10) R (00)
RED 00
GREEN 01
YELLOW 10
t=0

7. FINITE STATE
MACHINES
Finite State Machines (FSMs) play a crucial
role in understanding decision-making
logic and controlling digital systems.
In an FSM, the outputs and the next state
depend on the present state and the input
function. These state machines are
essential for designing sequential circuits
and modeling behavior in digital systems.
Digital
Logic
Design

8. Digital Circuits
Output depends on the present inputs
and the present state of the memory
elements.
Output depends on the present inputs.
Sequential Circuits
Combinational Circuits

9. SequentialCircuits
Output depends on the present inputs
and the present state of the memory
elements.
The output of the sequential depends
on the present inputs as well as what
is presently stored in the memory.

10. SequentialCircuits
Consider the Example of Changing
Channels on the Television using the
next channel button.
In the channel changing process the
output of the next channel depends
on the past channel.
For example, channel 2 will come after
1, channel three will come after 2.

11. Latches Flip-Flops
1 2
SequentialCircuits
Memory Elements
Level Trigger Edge Trigger

12. What Actually is FSM ?
A Finite State Machine (FSM) is a mathematical model used to represent and
control the behavior of systems that can exist in a finite number of states at
any given time. We will explain it further with a daily life example.

13. Building Blocks of FSMs
States represent
specific conditions or
configurations of the
system.
Finite set, Distinctness,
Initial state, Transition-
dependent .
States
Transitions define how
the FSM moves from
one state to another
based on input events.
Deterministic, Non-
deterministic,
Represented as arrows .
Transitions
Inputs trigger
transitions.
 Events, signals, or
conditions.
• Influence state
changes
Inputs
Describes how
outputs are
generated based on
states and inputs.
• Mealy State Machine
• Moore State
Machine
Output

15. FINITESTATEMACHINES

16. Moore State Machine
Mealy State Machine
Outputs depend on both
current inputs and states.
More flexible in terms of
output generation.
Outputs depend only on the
current state.

17. Mealy Machine Circuit Diagram

18. Moore Machine Circuit Diagram

19. REPRESENTATION
OF BEHAVIOUR
R P A S U M M E R 2 0 2 0
 State Transition Diagram:
 Pictorial
 State Table
 Tabular
 State Equations
 Algebraic
Here we only discuss State Transition
Diagram.

20. • Each Possible Output State is represented as a
Circle.
• Transitions from one state to another is
represented by an arrow.
So, that is how the State Diagram represents the behavior of
the finite state machines or any sequential circuit in a pictorial
way.
• The Value on the arrow indicates the input which
lead to the state transition.
STATE TRANSITION
DIAGRAM
• The value next to the input represents the output
for that input.

21. Mealy State Diagram
State Table

22. Moore State Diagram
State Table

23. Fetch-Decode-Execute Example
1

24. Fetch Decode Execute
States: S0 (Fetch): Initial state where the CPU fetches the
instruction.
S1(Decode):State where the CPU decodes the fetched
instruction.S2 (Execute): State where the CPU executes
the decoded instruction.
Transitions: S0 (Fetch) to S1 (Decode): Transition
triggered when the fetch of an instruction is complete.S1
(Decode) to S2 (Execute): Transition triggered when the
decode of the instruction is complete and the CPU is
ready to execute it.S2 (Execute) to S0 (Fetch): Transition
back to the fetch state after the execution of the current
instruction is complete, indicating readiness to fetch the
next instruction.
Outputs/Actions: These are the actions taken upon
entering each state or during transitions, such as
fetching an instruction, decoding it, and executing it.

25. Role of FSMs in CPU Design
Instruction Decoding:
FSMs help decode instructions fetched from memory. They
determine which operation (e.g., addition, subtraction, load,
store) the CPU should perform based on the opcode.
Control Signals:
FSMs generate control signals that activate specific
components (e.g., ALU, registers, memory) within the CPU.
These signals coordinate the execution of instructions.
State Transitions:
FSMs transition between states (e.g., fetch, decode, execute)
as the CPU progresses through the instruction cycle. Each state
corresponds to a specific phase of instruction processing.

26. TVSystemExample
Imagine you’re using a TV remote to change channels. The TV system
can be modeled as an FSM. Let’s break it down:
States
Off: The TV is turned off.
On: The TV is powered on.
Channel 1, Channel 2, …, Channel N: Different TV channels.
Transitions
When you press the power button, the system transitions
from Off to On.
When you press the channel up or down button, the system
transitions from one channel to another.
Actions:
Changing channels (switching from one state to another) is an
action.
Turning the TV on or off is also an action.

27. TVSystemExample
So, in this example:
The TV remote (and the TV itself) follows a set
of rules (states, transitions, and actions).
Each button press corresponds to a transition
between states (e.g., from Channel 1 to
Channel 2).
In summary, FSMs help us understand and
design systems with discrete and sequential
behavior, like changing TV channels! 📺

28. Natural Language
Processing FSM
States:
 Start
 Reading Noun
 Reading Verb
 End.
In natural language processing,
FSMs help parse sentences.

30. Programmable Logic
Devices
Design and working of
1-PROM
2-PLA
3-PAL

35. Programmable Logic
Array

37. @MuhammadBilal
THANKS
JAZAKALLAH!
Ms. Sehar Aftab
A special thank you to each of you for being part
of this journey. Your support fuels our passion for
creating impactful work..
From All of Group Members