I2 C Application Note - Basic Guide - Reserved Addresses, Clock Arbitration and Timing Specifications

Sep 18, 2026

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Communication between microcontrollers and peripheral devices relies on digital protocols. This application note introduces I2C as a widely used bus protocol across TI product families, covering its background, operational speed modes, physical-layer signaling, and data frame structure. It also provides practical examples using data converters, then extends into uncommon behaviors such as reserved addressing, clock arbitration and stretching, electrical timing/voltage requirements, and pullup resistor calculation.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages32

Reading Time1 h 21 min

AccessFree to download

I2C Overview

I2C Physical Layer

I2C Protocol

I2C Examples

Reserved Addresses

Advanced Topics

Protocols Similar to I2C

Summary

Application Note A Basic Guide to I2 C Joseph Wu ABSTRACT Communication between microcontrollers and different peripheral devices require some sort of digital protocol. I2C is a common communication protocol that is used in a variety of devices from many different product families produced by TI. This application note begins with a basic overview of the I2C protocol, describing the history of the protocol, different I2C speed modes, the physical layer of the digital communication, and the structure of the data. Several examples of the communication protocol are shown with different data converters. Finally, this application note covers some uncommon aspects of the protocol, including reserved addresses, clock arbitration and stretching, electrical timing and voltage specifications, and pullup resistor calculation. Table of Contents 1 I2C Overview............................................................................................................................................................................3 2 I2C Physical Layer...................................................................................................................................................................4 3 I2C Protocol............................................................................................................................................................................. 7 4 I2C Examples........................................................................................................................................................................... 9 5 Reserved Addresses............................................................................................................................................................ 15 6 Advanced Topics.................................................................................................................................................................. 20 7 Protocols Similar to I2C........................................................................................................................................................31 8 Summary............................................................................................................................................................................... 31 List of Figures Figure 2-1. Typical I2C Implementation........................................................................................................................................4 Figure 2-2. Open-Drain Connection Pulls Line Low When NMOS is Turned On.........................................................................5 Figure 2-3. Pullup Resistor Pulls Line High When NMOS is Turned Off..................................................................................... 5 Figure 2-4. Comparison Between Open-Drain and Push-Pull Contention ..................................................................................6 Figure 3-1. I2C START and STOP............................................................................................................................................... 7 Figure 3-2. I2C Digital One and Zero Representations................................................................................................................ 7 Figure 3-3. I2C Address and Data Frames.................................................................................................................................. 8 Figure 4-1. DAC80501 Functional Block Diagram.......................................................................................................................9 Figure 4-2. Example Write to the DAC Data Register of the DAC80501 ................................................................................... 10 Figure 4-3. ADS1115 Functional Block Diagram......................................................................................................

FAQs

What is I2C used for in microcontroller systems?

I2C provides a digital communication protocol connecting microcontrollers to various peripheral devices. It is commonly used across device families produced by TI.

Which topics does the guide cover about the I2C protocol?

The note covers I2C overview and history, speed modes, the physical layer, and the structure of data. It also includes examples and advanced behaviors such as reserved addresses and clock arbitration/stretching.

What advanced electrical and timing details are included?

The guide includes electrical timing and voltage specifications and explains how to calculate pullup resistors. These help ensure correct bus behavior under the required signaling conditions.

Sep 18, 2026

Upload by Bintang