I²C is a two-wire, bi-directional serial bus that provides a simple and efficient method of data exchange between devices. It is most suitable for applications requiring occasional communication over a short distance between many devices.

The I²C standard is a true multi-master bus including collision detection and arbitration that prevents data corruption if two or more masters attempt to control the bus simultaneously.

The interface defines 3 transmission speeds:

• Normal: 100Kbps
• Fast: 400Kbps
• High speed: 3.5Mbps

Only 100Kbps and 400Kbps modes are supported directly. For High speed special IOs are needed. If these IOs are available and used, then High speed is also supported.

More information can be found at https://opencores.org/projects/i2c