NXP Semiconductors (formerly Philips Semiconductors) developed an easy to use bidirectional 2-wire bus for efficient inter-integrated circuit control. This bus is called the Inter-Integrated Circuit-bus or I²C-bus.

The I²C-bus has become a de facto world standard; implemented in over 2,500 different integrated circuits (ICs) and licensed to more than 50 companies. Additionally, the versatile I²C-bus is used in a variety of control architectures such as System Management Bus (SMBus), Power Management Bus (PMBus), Intelligent Platform Management Interface (IPMI), and Advanced Telecom Computing Architecture (ATCA).

Originally, the I²C-bus was limited to a bit rate up to 100 kbit/s, commonly referred to as the Standard-mode (Sm). Many of today‘s applications, however, require longer buses, higher bus speeds and/or lower supply voltages. As a result thereof, there are now 4 operating speed categories:

• Standard-mode (Sm), with a bit rate up to 100 kbit/s;
• Fast-mode (Fm), with a bit rate up to 400 kbit/s;
• Fast-mode Plus (Fm+), with a bit rate up to 1 Mbit/s; and
• High-speed mode (Hs-mode), with a bit rate up to 3.4 Mbit/s.

NXP Semiconductors owns a number of patents for essential features and advantageous I²C implementations on  UM10204_3 I²C bus specification v3-0 Jun 2007 (which is an extension of the  I²C bus specification v2-1 Jun 2000). Any use of these patents requires a license from NXP Semiconductors.

All of the above patents are licensed in a bundled license package together with NXP Semiconductors‘ I²C-bus logo.

It is expressly noted that such license shall also be required by companies which obtained a license from Royal Philips Electronics‘ under its patents pertaining to the Sm and/or Fm modes and whose products use NXP Semiconductors‘ patents.

For further details regarding NXP Semiconductors I²C license program, please contact NXP Semiconductors here. Ethan Andelman

More information concerning I²C slave address allocation service.