Editing I²C (section)

==Signalling==
The protocol is controlled by the master microcontroller. The master is clocking the bus on the SCLK line, and either device is sending a bit on the SDA line on each clock depending on that particular slave device's protocol.

Each transaction begins with the master sending a START bit, followed by an ''address byte'' with the address to the slave device to receive the transaction.
If the higher bits of the first byte is 1-1-1-1, the address is instead in encoded in two bytes.
Only the slave with the matching address should act on a transaction.
Multiple more bytes can then follow, followed by a STOP bit.

Values are sent most-significant-bit first (multi-byte values are thus sent in big-endian byte order).