20.4.2.1.6 Address Detect

Address Detect mode is used when multiple receivers are connected to a transmitter. It allows a receiver to determine if the message is intended for it and to ignore those that are not. If the ninth data bit is a ‘1’, the data are recognized as addresses to be processed by the receiver. An address mask is provided to allow multiple receivers to accept the same address.

If an address match is successful, the unmasked address is present in UxRXB and an RX interrupt is generated. If the address match is not successful, all of the following data are ignored until a byte with the ninth bit set is received.

In 8-Bit Address Detect mode, the transmitted address IDs are written to Parameter 1. For receivers, the expected address is written to Parameter 2 (P2[7:0]) and the mask value to Parameter 3 (P3[7:0]). Mask bit values of ‘1’ will include the respective bit position in the compare, whereas a ‘0’ indicates a ‘don’t care’. A mask value of 0x00 will accept all address values, effectively disabling the address detect feature. A mask value of 0xFF will allow only one matching value.