AXI Bridge for PCI Express v2.4
36
PG055 June 4, 2014
Chapter 2:
Product Specification
Root Port Interrupt FIFO Read Register 1 (Offset 0x158)
Reads from this location return queued interrupt messages. Data from each read follows the
format shown in
. For MSI interrupts, the message payload is presented in the
Root Port Interrupt FIFO Read 2 register. The interrupt-handling flow should be to read this
register first, immediately followed by the Root Port Interrupt FIFO Read 2 register. For
non-Root Port cores, reads return zero.
Note:
Reads are non-destructive. Removing the message from the FIFO requires a write to either
this register or the Root Port Interrupt FIFO Read 2 register. The write value is ignored.
Table 2-19:
Root Port Error FIFO Read Register
Bits
Name
Core
Access
Reset
Value
Description
15:0
Requester ID
RWC
0
Requester ID belonging to the requester of the error message.
17:16 Error Type
RWC
0
Indicates the type of the error.
00b: Correctable
01b: Non-Fatal
10b: Fatal
11b: Reserved
18
Error Valid
RWC
0
Indicates whether read succeeded.
1b: Success
0b: No message to read
31:19 Reserved
RO
0
Reserved
Table 2-20:
Root Port Interrupt FIFO Read Register 1
Bits
Name
Core
Access
Reset
Value
Description
15:0
Requester ID
RWC
0
Requester ID belonging to the requester of the error message.
26:16 MSI Address
RWC
0
For MSI interrupts, contains address bits 12:2 from the TLP
address field.
28:27 Interrupt Line
RWC
0
Indicates interrupt line used.
00b: INTA
01b: INTB
10b: INTC
11b: INTD
For MSI, this field is set to 00b and should be ignored.
29
Interrupt Assert
RWC
0
Indicates assert or deassert for INTx.
1b: Assert
0b: Deassert
For MSI, this field is set to 0b and should be ignored.
30
MSI Interrupt
RWC
0
Indicates whether interrupt is MSI or INTx.
1b = MSI, 0b = INTx.
31
Interrupt Valid
RWC
0
Indicates whether read succeeded.
1b: Success
0b: No interrupt to read