15:8

0h

RW

Opcode (OPCODE)

This is the Opcode sent in the IOSF sideband message.

7

0h

RW

Posted (POSTED)

When set to 1, the message will be send as a posted message instead of non-posted. This should only be used if the receiver is known to support posted operations for the specified operation.

6:3

0h

RO

Reserved

2:1

0h

RW/V

Response Status (RESPONSE)

00 - Successful
01 - Unsuccessful / Not Supported
10 - Powered Down
11 - Multi-cast Mixed

This register reflects the response status for the previously completed transaction. The value of this register is only meaningful if SBISTAT.INITRDY is zero.

0

0h

RW/1S

Initiate/ Ready# (INITRDY)

0: The IOSF sideband interface is ready for a new transaction
1: The IOSF sideband interface is busy with the previous transaction.
A write to set this register bit to 1 will trigger an IOSF sideband message on the private IOSF sideband interface. The message will be formed based on the values programmed in the Sideband Message Interface Register Access registers.
Software needs to ensure that the interface is not busy (SBISTAT.INITRDY is clear) before writing to this register.