I2C Bus Technology: Benefits and Uses

The I2C transport may be a straightforward, bidirectional two-wire synchronous serial transport created by Philips. It as it were requires two lines (serial clock line and serial information line) to transmit data between gadgets associated to the transport.

Its main features are as follows:

1. The transport as it were needs two lines: serial clock line (SCL) and serial information line (SDA).

2. Each gadget associated to the transport can be extraordinarily tended to by computer program, building up a basic master/slave relationship. The ace gadget can act as both a transmitter and a recipient.

3. The I2C transport bolsters multi-master control with competition discovery and assertion circuits, permitting different ace gadgets to send information at the same time without adulterating the information on the transport.

4. Synchronous clock allows devices to communicate at different baud rates.

5. The synchronous clock can also serve as a handshake signal to stop or restart the serial interface.

6. The number of integrated circuits connected to the bus is only limited by the maximum bus capacitance of 400 pF.

The I2C bus greatly simplifies system design, as the bus interface is already integrated into the chip, shortening design time. Removing or adding integrated circuit chips in the system does not affect other chips on the bus.

The I2C bus achieves addressing and information transmission between devices through SDA and SCL lines. Each module has a unique address. During transmission, the circuit module on the bus may be the master controller (such as a microcontroller) or a slave controller, and can be a transmitter or receiver, depending on its function.

During data transmission, the circuit module acting as the master controller initializes the data transmission and provides the clock on the I2C bus. The object, direction, start, and end of the information transmission are determined by the master controller. The circuit module addressed by the master controller on the I2C bus is called the slave controller. Data is sent by the transmitter and received by the receiver. The receiver sends an acknowledgment signal on the SDA line after correctly receiving each data byte.

The I2C transport bolsters numerous ace control, meaning there can be numerous ace controllers (microcontrollers with I2C transport) controlling the transport at the same time. Concurring to distinctive working states, the circuit modules on the I2C transport can be classified as ace transmitter, ace recipient, slave transmitter, and slave recipient. Intelligent circuits like microcontrollers can work in any of these four states, while some memory devices like PAM and EPROM can only be slave transmitters or slave receivers.

The typical I2C bus application system structure is shown in Figure 1.

Figure 1: Typical I2C bus

The bus can connect multiple microcontroller application systems and multiple devices with I2C interfaces. Each I2C interface serves as a node, with the number and type of nodes mainly limited by the total capacitance and address capacity. The 8XC552 microcontroller has an I2C interface and can be directly connected to the I2C bus. Microcontrollers without I2C interfaces can expand the I2C interface through the PCD8584 expansion chip.