9.7.5.9.1 I3C Hot-Join Request (HJ)

If the received IBI ID matches the hot-join ID (0x02, RnW=0), then the response for the received HJ request is based on the programmed HJ Response Control.

If the HJ Response Control is set to ‘0’, then the controller responds to the HJ request with ACK and sets IBI_STS to ACK to indicate to the application that the controller has ACK’ed the received HJ request.

If the HJ Response Control is set to ‘1’, then the controller responds to the HJ request with a NACK followed by 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 the IBI Status Data Structure (see IBI Status 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 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.