Message Signaled Interrupt Message Data (MSI_MD) – Offset 8C
Message Signaled Interrupt Message Data
Bit Range | Default | Access | Field Name and Description |
15:0 | 0x0 | RW | Data (DATA) This 16-bit field is programmed by system software if MSI is enabled. Its content is driven onto the lower word (PCI AD(15:0)) during the data phase of the MSI memory write transaction. The Multiple Message Enable field (bits 6-4 of the Message Control register) defines the number of low order message data bits the function is permitted to modify to generate its system software allocated vectors. For example, a Multiple Message Enable encoding of 010 indicates the function has been allocated four vectors and is permitted to modify message data bits 1 and 0 (a function modifies the lower message data bits to generate the allocated number of vectors). If the Multiple Message Enable field is 000, the function is not permitted to modify the message data. |