Introduction

Inter-Integrated Circuit, more commonly referred to as I²C, is a synchronous, two-wire, bidirectional serial communications bus. The I²C module can be used to communicate with other I²C compatible EEPROMs, display drivers, sensors, or other microcontroller devices. This technical brief discusses the features and functions of the stand-alone I²C module in Slave mode. The stand-alone I²C module should not be confused with the traditional Master Synchronous Serial Port (MSSP), which contained both I²C and Serial Peripheral Interface (SPI) functions.

The I²C module provides the following operational modes and features:

• Master Mode
• Slave Mode with Byte NACKing
• Multi-Master Mode
• Dedicated Receive and Transmit Buffers
• Up to Four Dedicated Slave Address Registers⁽¹⁾
• 7-Bit and 10-Bit Addressing with Masking
• General Call Addressing
• Interrupts
• Bus Collision Detection
• Bus Time-Out Detection with Programmable Sources
• SDA Hold Time Selection
• Programmable Bus-Free Time Selection
• I²C, SMBus 2.0, and SMBus 3.0 Input Level Selection
• Direct Memory Access (DMA) Support⁽²⁾