fsmlog

A tool for converting finite state machine to verilog code

Embedded Systems Course Optional Assignment - Spring 2023

Parsa Mohammadian - 98102284

Table of Contents

• Installation
• Usage
  • Validate
  • Convert
• Specifications
• Technical Details
• Example

Installation

From pypi:

pip install fsmlog

From source:

make install

Usage

You can use --help to get more information about the usage of each command.

The tool consists of two commands: validate and convert.

Validate

The validate command is used to validate the input file. It will check if the input file is a valid finite state machine according to the tool's specifications. It takes one argument: the path to the input file.

Convert

The convert command is used to convert the input file to verilog code. It takes two arguments: the path to the input file and the path to the output file. If the output file is not specified, the output will be printed to the console.

Specifications

The input file must be a valid json file with the following structure:

{
    "inputs": [],
    "outputs": [],
    "states": [],
    "initial_state": "",
}

The inputs and outputs fields are lists of registers. Each register has the following structure:

{
    "name": "",
    "length": 0
}

The states field is a list of states. Each state has the following structure:

{
    "name": "",
    "transitions": [],
    "outputs": {}
}

The outputs field is just key-value pairs of the output registers. The transitions field is a list of transitions. Each transition has the following structure:

{
    "destination": "",
    "condition": ""
}

The condition field must be a valid verilog boolean expression.

Valid input file examples can be found in the example directory.

Technical Details

The tool uses jinja2 to generate the verilog code. The template.v file can be found in the src directory. This template can be populated with the FiniteStateMachine object named fsm. The FiniteStateMachine object is created from the input file using the FiniteStateMachine.from_json method. The FiniteStateMachine class has similar attributes to the input file's structure. The FiniteStateMachine class can be found in the src/model/fsm.py file.

Example

Consider the following finite state machine:

We can encode this finite state machine as specified in specifications. The encoded file can be found in the example directory. The file is named air-conditioning.json.

The following command will validate the input file:

fsmlog validate example/air-conditioning.json

FSM example/air-conditioning.json is valid

Now we can convert the input file to verilog code:

fsmlog convert example/air-conditioning.json --output example/air-conditioning.v

The generated verilog code can be found in the example directory. The file is named air-conditioning.v.

The resulting verilog code can be both simulated and synthesized.