26.9.3 TWI (Slave) Address Register n

The TWARn should be loaded with the 7-bit Slave address (in the seven most significant bits of TWARn) to which the TWI n will respond when programmed as a Slave Transmitter or Receiver, and not needed in the Master modes. In multi-master systems, TWARn must be set in masters which can be addressed as Slaves by other Masters.

The LSB of TWARn is used to enable recognition of the general call address (0x00). There is an associated address comparator that looks for the slave address (or general call address if enabled) in the received serial address. If a match is found, an interrupt request is generated.

Name: TWAR
Offset: 0xBA + n*0x20 [n=0..1]
Reset: 0x02
Property: -

Bit 76543210 
 TWA[6:0]TWGCE 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000010 

Bits 7:1 – TWA[6:0] TWI (Slave) Address

These seven bits constitute the slave address of the TWI n unit.

Bit 0 – TWGCE TWI General Call Recognition Enable Bit

If set, this bit enables the recognition of a General Call given over the two-wire Serial Bus n.