24.4.4.3.1 I³C Hot-Join (HJ) Request

If the received IBI ID matches the Hot-Join ID (7’b0000010, RnW = 0), then the response to the received HJ request is based on the programmed value of I3CxCNTRL[HOTJOIN].

If the I3CxCNTRL[HOTJOIN] is set to 0, the controller responds to the HJ request with ACK and sets the ‘IBI_STS’ field in IBI Queue Data Structure to ACK to indicate to the application that the controller has ACK’d the received HJ request.

If the I3CxCNTRL[HOTJOIN] is set to 1, the Controller responds to the HJ request with a NACK followed by issuing a broadcast DISEC CCC command (DISHJ bit set) with the RESTART condition. This disables the HJ request generation from all the unaddressed devices at that instant. The Controller sets the ‘IBI_STS’ field in IBI Queue Data Structure to NACK to indicate to the application that the Controller has rejected the received HJ request. The application can optionally set the HJ Reject Notify Control (I3CxIBIQNOTIFY) to get an IBI status for a rejected HJ request. Otherwise, the Controller moderates the IBI Status generation for rejected HJ requests.

Based on the IBI status for the HJ request, the application must issue the ENTDAA to assign the dynamic address for the devices that generate the HJ request.