I2C bus history was started in 1992, when Philips company released its first specification version 1.0. This specification precluded the setting of the slave device address programmatically as the most difficult procedure. Along with the standard mode data transfering rates of 100 kbit/s (low-speed), fast transfer mode (fast-speed) was introduced with speeds up to 400 kbit/s. 1O-bit addressing mode has been appeared also.
You can use USB-I2C Adapters from Diolan to develop and debug your I2C bus application.
Version 2.0 was released in 1998 and introduced a high-speed bus specification mode (Hs-mode) with a transfer rate up to 3.4 Mbit/s. And there were requirements for compatibility with low-speed and fast-speed modes. By the time when version 2.0 has been appeared, I2C bus has been spread worldwide, becoming an international standard. There were developed more than 1000 integrated circuits, the official license for using specifications, was acquired by more than 50 companies. Version 2.1, which is dated by 2000, includes minor modifications which are not reflected in version 2.0. At the time of this writing, version 2.1 is the latest valid version released by Phillips.