This document provides a detailed explanation of the Verilog code for implementing I2C (Inter-Integrated Circuit) communication between a master and a slave device. The code consists of two main modules: I2C_Master
and I2C_Slave
. Below, we break down each module's functionality and structure.
The I2C_Master
module represents the I2C master device responsible for initiating and managing communication with one or more slave devices. Here's a detailed breakdown of its functionality:
The core of the I2C_Master
module is a state machine that controls the I2C communication protocol. It progresses through the following states:
- IDLE_STATE: The initial state where the module waits for a start condition.
- START_STATE: This state generates a start condition by driving the SDA (Serial Data) line low while the SCL (Serial Clock) line is high.
- WRITE_STATE: In this state, the module writes data to the SDA line and shifts the data for each clock cycle. It determines whether to continue writing or transition to the STOP_STATE.
- STOP_STATE: Here, the module generates a stop condition by driving the SDA line high while SCL is high.
- start: This output signal is high when the module is in the START_STATE, indicating a start condition.
- stop: Similarly, this output signal is high when the module is in the STOP_STATE, indicating a stop condition.
- write: This signal determines whether the module should continue writing data in the WRITE_STATE or transition to the STOP_STATE.
- ack: The
ack
input signal represents the acknowledgment (ACK) signal received from the slave. It is used to determine if the slave acknowledges the data sent by the master.
- The module initializes its state machine to the IDLE_STATE during reset (
rst_n
signal).
To use the I2C_Master
module, you need to instantiate it within your FPGA or ASIC design and connect the appropriate clock (clk
), reset (rst_n
), and control signals (start
, stop
, write
, and ack
) as required by your application. Customize the data and address signals as needed.
The I2C_Slave
module represents the I2C slave device responsible for responding to the master's requests. Below is a detailed explanation of its functionality:
The core of the I2C_Slave
module is a state machine that manages the I2C communication protocol. It includes the following states:
- IDLE_STATE: This is the initial state where the module waits for a start condition.
- ADDRESS_STATE: In this state, the module waits for the master to send its address. Once the address is received, it transitions to the READ_STATE.
- READ_STATE: Here, the module waits for clock edges to receive data from the master.
- ack: The
ack
output signal indicates whether the slave acknowledges the master's address during the ADDRESS_STATE.
- The module initializes its state machine to the IDLE_STATE during reset (
rst_n
signal).
To use the I2C_Slave
module, you need to instantiate it within your FPGA or ASIC design and connect the appropriate clock (clk
), reset (rst_n
), and communication signals (sda
, scl
, and ack
) as needed for your application. Customize the data and address handling logic as per your requirements.