Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs
5.8.6.6.9. Master Request Generation
The I3C controller can generate the Master Request (MR) in non-current master mode to request for I3C bus ownership from the current master.
The application of the I3C controller can decide to send a Master Request by asserting the MR bit in the Slave Interrupt Request register.
The status of the IBI generation is updated in the IBI_STS field of Slave Interrupt Request register (SLV_INTR_REQ), which is informed to the application by the IBI_UPDATED_STS interrupt in INTR_STATUS register by I3C controller. Also after IBI_STS is updated, the MR bit in SLV_INTR_REQ register is auto cleared. On receiving this interrupt, the slave application can read the IBI_STS field in the Slave Interrupt Request register.
| IBI_STS | Value | Description | 
|---|---|---|
| Reserved | 00 | Default value | 
| Success | 01 | MR accepted by the master (ACK response received). | 
| Reserved | 10 | Reserved | 
| Not Attempted | 11 | MR not attempted | 
The controller does not attempt to issue the IBI and generates the Not Attempted (2'b11) status under the following conditions.
- Master has not assigned the dynamic address.
- Master has cleared the assigned dynamic address through RSTDAA.
- Master has disabled the MR_EN through DISEC CCC (MR_EN in SLV_EVENT_STATUS register).
- The controller has switched the role to master (applicable only for secondary master configuration).
The following are the SIR-related registers for the I3C controller. For more information, refer to the I3C Controller Address Map and Register Definitions section.
- IBI_UPDATED_STAT
- SLV_INTR_REQ
- SLV_EVENT_STATUS
- BUS_FREE_AVAIL_TIMING