14.2.1.3 Address Comparator

When a master transmits a slave address on the bus, the address comparator checks the 7-bit slave address with its own slave address. If the transmitted slave address does not match, the address comparator compares the first received byte with the general call address (0x00). If the address matches, the status register is updated. The general call address is used to address each device connected to the I2C-bus.