1. Finite State Machines (FSM)
Ain Shams University
Faculty of Engineering
Integrated Circuits Lab
Finite State Machines (FSM)
Presented by:
Sameh Assem Ibrahim

2. Digital Still Camera Block Diagram
Controllers can be implemented using FSM.
They control the operation of sequential circuits.
A controller is a part of any system block diagram.
A single system may contain more than one controller.
PC Block Diagram
Bluetooth
Chip
Digital Still Camera Block Diagram
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
26 November 2002

3. The Fourth Year Student example
An abstract machine consisting of a set of states (including the initial state), a set of input events, a set of output events and a state transition function. The function takes the current state and an input event and returns the new set of output events and the next state.
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
The Fourth Year Student example
26 November 2002

4. States Transitions Inputs Events Outputs Actions Events Outputs
An event is an occurrence that may cause the state of a system to change; it has no duration and can precede or follow another event. An event conveys information.
An event is a change in one of the input signals.
Outputs
These are the control signals coming out of the FSM to control the data flow in the system and to enable or disable blocks.
Again they are as any output signal in a VHDL entity.
Actions
A “task” defined by the current state that takes place due to an event
An event is a change in the outputs of the FSM.
Inputs
Inputs are normal input signals as any VHDL entity. They are used as the control signals of the FSM.
2 input signals must be included in any FSM:
1- Clock (FSM is a sequential circuit)
2-Reset (Which initiates the operation in the start state)
Transitions
A state transition indicates that the FSM in the source state will perform certain specified actions and enter the destination state when a specified event occurs or when certain conditions are satisfied. A state transition is a relationship between two states. You can show one or more state transitions from a state as long as each transition is unique.
States
A state represents a condition or situation during the life of a FSM during which it satisfies some condition or waits for some event. Each state represents the cumulative history of its behavior.
We have 3 types of states:
1- Start state
2- Simple State
3- Idle State
States
Transitions
Inputs
Events
Outputs
Actions
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
26 November 2002

5. FSM FSM FSM FSM Inputs Outputs State Current State Inputs are changed
(Event)
(Transition)
Outputs are changed
(Action)
Inputs
FSM
Outputs
State
Current State
Inputs are changed
(Event)
(Transition)
Inputs
FSM
Outputs
State
Current State
Inputs are changed
(Event)
Inputs
FSM
Outputs
State
Current State
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
26 November 2002

6. Determine the various states of the system.
Determine the inputs and the outputs to the FSM to obtain the required data flow and produce the required control signals.
Perform a state minimization.
Design the FSM either by writing a VHDL code or by using a state diagram editor (Renoir or HDL designer series included in FPGA Advantage)
Simulate for Verification.
Synthesize.
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
26 November 2002

7. SAFER+ Algorithm Controller
(used in Bluetooth Security)
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
Block Diagram
26 November 2002

8. SAFER-Controller (FSM)
-The need for FSM
-What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
SAFER-Controller (FSM)
26 November 2002

9. RTL Schematic -The need for FSM -What is a FSM? (Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
RTL Schematic
26 November 2002

10. Digital Camera Block Diagram -The need for FSM -What is a FSM?
(Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
Block Diagram
26 November 2002

11. State Diagram -The need for FSM -What is a FSM? (Initial Example)
-FSM components
-Design Steps
-Implemented Example
-Exercise
State Diagram
26 November 2002