27.5.15 Client Address Mask

Name: SADDRMASK
Offset: 0x0E
Reset: 0x00
Property: -

Bit 76543210 
 ADDRMASK[6:0]ADDREN 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 

Bits 7:1 – ADDRMASK[6:0] Address Mask

The ADDRMASK bit field acts as a second address match or an address mask register depending on the ADDREN bit.

If the ADDREN bit is written to ‘0’, the ADDRMASK bit field can be loaded with a 7-bit Client Address mask. Each of the bits in the Client Address Mask (TWIn.SADDRMASK) register can mask (disable) the corresponding address bits in the TWI Client Address (TWIn.SADDR) register. When a bit from the mask is written to ‘1’, the address match logic ignores the comparison between the incoming address bit and the corresponding bit in the Client Address (TWIn.SADDR) register. In other words, masked bits will always match, making it possible to recognize the ranges of addresses.

If the ADDREN bit is written to ‘1’, the Client Address Mask (TWIn.SADDRMASK) register can be loaded with a second client address in addition to the Client Address (TWIn.SADDR) register. In this mode, the client will have two unique addresses -- one in the Client Address (TWIn.SADDR) register and the other in the Client Address Mask (TWIn.SADDRMASK) register.

Bit 0 – ADDREN Address Mask Enable

If this bit is written to ‘0’, the TWIn.SADDRMASK register acts as a mask to the TWIn.SADDR register.

If this bit is written to ‘1’, the client address match logic responds to the two unique addresses in the client TWIn.SADDR and TWIn.SADDRMASK registers.