| Field Name | Bits | Type | Reset Value | Description |
|---|
| Reserved | 31:25 | roRead-only | 0x0 | |
| msg_has_data | 24 | rwNormal read/write | 0x0 | Message Payload Presence. When msg_has_data == 1, msg_data is the data payload transmitted with the message. msg_has_data must be consistent with msg_code. |
| msg_tag | 23:16 | rwNormal read/write | 0x0 | Message Tag[7:0]. Byte 6 of the Message TLP Header. Set to 0x0 if the Tag field is unused by the message. |
| msg_code | 15:8 | rwNormal read/write | 0x0 | Message Code[7:0]. Byte 7 of Message TLP Header. Defines the type of Message. Message Codes are defined by the PCI Express Specification and associated ECNs. |
| msg_fmt_type | 7:0 | rwNormal read/write | 0x0 | Message Format and Type. Byte 0 of Message TLP Header. Must be consistent with Message Code. |