9.7.5.3.2 IBI Status Descriptor
The IBI status descriptor is a read-only structure describing an IBI event received from a target device on the I3C bus.
| Bits | Field Name | Access Type | Reset Value | Description |
|---|---|---|---|---|
| 31 | IBI_STS | R | 0x0 | IBI Status Indicates the status of the response returned for the received IBI. 0: The received IBI is responded with ACK. Any non-zero value of the DATA_LENGTH field indicates the presence of data payload for the ACK’ed IBI. 1: The received IBI is responded with NACK. An Auto Disable CCC command is issued if the received IBI address is valid and matching with the DAT entry. If an IBI is received from an unknown address (not a valid entry in DAT), the IBI_STS is set to ‘1’. |
| 30 | ERROR | R | 0x0 | Error Indicates that during IBI Auto command, an error is encountered and the data from the target device is partially or fully discarded. The following errors are detected:
|
| 29 | Reserved | – | – | – |
| 28:26 | HW_CONTEXT | R | 0x0 | IBI Hardware Context Hardware specific context for IBI processing. Opaque for driver. This field is reserved for the I3CC. |
| 25 | TS | R | 0x0 | IBI Timestamp Present Indicates whether a timestamp is available for the IBI. Values:
|
| 24 | LAST_STATUS | R | 0x0 | Last Status When set, indicates that this status is the last for the received IBI. If the payload of the received IBI exceeds the programmed IBI data threshold, then the I3CC splits the IBI payload into multiple chunks of IBI_DATA_THLD size (max) which includes the timestamp bytes, if enabled. |
| 23:16 | Reserved | – | – | – |
| 15:8 | IBI_ID | R | 8’h00 | IBI Identifier This field indicates the target address byte along with the R/W bit received from the target device. |
| 7:0 | DATA_LENGTH | R | 8’h00 | IBI Data
Length Number of data bytes received from the target device either along with the IBI or with the Auto command (read). The data length is limited by I3CC_QUEUE_THLD_CTRL.IBI_DATA_THLD. |
The I3CC receives the bytes in the same order as on the bus and places the first byte received in the Least Significant Byte (LSB) position, and the following bytes in the LSB + 1 location, until all the four bytes of a word are received in the IBI queue. The data is always preceded with IBI status and indicates the number of valid IBI data bytes as shown in the following figure. See In-Band Interrupt (IBI) Detection and Handling for more information on how IBI status and data are packed and arranged in IBI queue.