Datasheet

23.9.3. TWI (Slave) Address Register
The TWAR should be loaded with the 7-bit Slave address (in the seven most significant bits of TWAR) to
which the TWI will respond when programmed as a Slave Transmitter or Receiver, and not needed in the
Master modes. In multi master systems, TWAR must be set in masters which can be addressed as
Slaves by other Masters.
The LSB of TWAR 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
Reset: 0xFE
Property: -
Bit 7 6 5 4 3 2 1 0
TWA6 TWA5 TWA4 TWA3 TWA2 TWA1 TWA0 TWGCE
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 1 1 1 1 1 1 1 0
Bits 1, 2, 3, 4, 5, 6, 7 – TWAn: TWI (Slave) Address
These seven bits constitute the slave address of the TWI unit.
Bit 0 – TWGCE: TWI General Call Recognition Enable Bit
If set, this bit enables the recognition of a General Call given over the 2-wire Serial Bus.
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
292