Systems, methods, and apparatus are configured to enable a receiver to provide feedback. A feedback mechanism enables a transmitting device to identify the provider of feedback for a multicast transmission, and the feedback transmitted by one or more individual receivers of the multicast transmission. A method includes receiving a multicast write command from the serial bus in a first datagram, writing a data byte received in a first data frame of the first datagram to a register address identified by the first datagram, and providing device-specific feedback regarding the first datagram in a multibit slot within the second data frame. The multibit slot is one of a plurality of sequential multibit slots defined for the second data frame. Each multibit slot in the plurality of sequential multibit slots may provide device-specific feedback from one receiving device addressed by the multicast write command.