Question

True or false. In I2C devices, each bit of information (data, address, ACK/NACK) is transferred with a single clock pulse.

Short answer

True, in I2C communication, each bit (data, address, ACK/NACK) is transferred with a single clock pulse.

Step-by-step solution

Understanding I2C Communication

I2C, which stands for Inter-Integrated Circuit, is a synchronous, multi-master, multi-slave, packet-switched, single-ended, serial communication bus. This means that data is transferred in synchronization with a clock signal.

Recognizing the Data Transfer Process

In I2C communication, each bit of information whether it is part of the address, data, or a part of the acknowledgement (ACK/NACK) signal, is transferred on the data line while the clock line is high. This indicates that each bit is indeed transferred with a single clock pulse.

Validating the Statement

Given the I2C protocol definition, the statement that each bit of information is transferred with a single clock pulse is true.

Key concepts

Synchronous Serial Communication

In the realm of digital electronics, synchronous serial communication is a method where data exchange is closely tied to a clock signal. This clock signal coordinates the timing of data transmission between two or more devices to ensure that all parties involved can accurately send and receive information. Unlike its counterpart, asynchronous communication, where data can be sent independently of a clock signal, synchronous communication necessitates both the sender and the receiver to operate in unison with a shared clock.

In the case of the I2C (Inter-Integrated Circuit) protocol, each data bit is transferred in sync with a clock pulse. This approach eliminates the need for the receiving device to guess when the next bit will arrive, leading to a more reliable and straightforward communication process. As the I2C devices share common data and clock lines, the devices on the bus need to function in harmony to avoid data collision and ensure integrity.

Multi-Master Multi-Slave Bus

The I2C communication protocol is distinct due to its multi-master, multi-slave bus configuration. This means that multiple 'master' devices can initiate communication and control the bus, while several 'slave' devices respond to the masters' requests. Every device connected to the bus has a unique address used for identification.

Configuration Benefits

Such a setup allows for flexibility and scalability in system design. For instance:

• A master device can be a microcontroller commanding peripheral sensors (slaves).
• If one master device fails, another can take over, enhancing system reliability.
• Additional master or slave devices can be added without significantly altering the overall system architecture.

Despite these advantages, managing bus arbitration—determining which master has control of the bus when conflicts arise—is crucial for a properly functioning multi-master system.

Serial Data Transfer

Serial data transfer in I2C involves sending data one bit at a time over a single wire or data line, which is quite efficient for long-distance communication with fewer physical connections. This contrasts with parallel communication, where multiple bits are sent simultaneously across several wires.

In I2C, the serial transfer is orchestrated by two lines only: the serial data line (SDA) and the serial clock line (SCL). Here's a simplified view of how this works:

• The master device generates a start condition, signals all devices connected to the bus, and selects a slave device by sending its unique address.
• Once a slave device acknowledges, the master sends or requests data in 8-bit packages.
• After each 8-bit data packet, an acknowledge bit (ACK/NACK) is exchanged to confirm successful receipt.
• The end of communication is marked by a stop condition from the master.

This method of data transmission is not only simple and reliable but also minimizes the wiring complexity of interconnected devices within a system.