Altera Stratix V Avalon-ST User Manual
Page 81
Bits
Register Description
Default Value
Access
[16]
MSI Enable. This bit must be set to enable the MSI interrupt
generation.
0
RW
[15:8]
Next Capability Pointer. Points to either MSI-X or Power
Management Capability.
0x68 or 0x78
RO
[7:0]
Capability ID. PCI-SIG assigns this value.
0x05
RO
Table 5-5: MSI Message Address Registers - 0x054 and 0x058
Bits
Register Description
Default Value
Access
[1:0]
The two least significant bits of the memory address. These are
hardwired to 0 to align the memory address on a Dword
boundary.
0
RO
[31:2]
Lower address for the MSI interrupt.
0
RW
[31:0]
Upper 32 bits of the 64-bit address to be used for the MSI
interrupt. If the
64-bit Addressing Capable
bit in the
MSI
Control
register is set to 1, this value is concatenated with the
lower 32-bits to form the memory address for the MSI interrupt.
When the
64-bit Addressing Capable
bit is 0, this register
always reads as 0.
0
RW
Table 5-6: MSI Message Data Register - 0x058 (32-bit addressing) or 0x05C (64-bit addressing) Register
Bits
Register Description
Default Value
Access
[15:0]
Data for MSI Interrupts generated by this function. This base
value is written to Root Port memory to signal an MSI interrupt.
When one MSI vector is allowed, this value is used directly. When
2 MSI vectors are allowed, the upper 15 bits are used. And, the
least significant bit indicates the interrupt number. When 4 MSI
vectors are allowed, the lower 2 bits indicate the interrupt
number, and so on.
0
RW
[31:16
Reserved
0
RO
UG-01097_sriov
2014.12.15
MSI Registers
5-7
Registers
Altera Corporation