Chapter 6: IP Core Interfaces
6–33
Interrupts for Endpoints when Multiple MSI/MSI-X Support Is Enabled
November 2012
Altera Corporation
Arria V GZ Hard IP for PCI Express
Interrupts for Endpoints when Multiple MSI/MSI-X Support Is Enabled
describes the IP core’s exported interrupt signals when you turn on
Enable
multiple MSI/MSI-X support
under the
Avalon-MM System Settings
banner in the
GUI. Refer to
for detailed information about all interrupt
mechanisms.
Interrupts for Root Ports
describes the signals available to a Root Port to handle interrupts.
Completion Side Band Signals
describes the signals that comprise the completion side band signals for the
Avalon-ST interface. The Arria V GZ Hard IP for PCI Express provides a completion
error interface that the Application Layer can use to report errors, such as
programming model errors. When the Application Layer detects an error, it can assert
the appropriate
cpl_err
bit to indicate what kind of error to log. If separate requests
result in two errors, both are logged. The Hard IP sets the appropriate status bits for
Table 6–10. Exported Interrupt Signals for Endpoints when Multiple MSIMSI-X Support is Enabled
Signal
I/O
Description
msi_intf[81:0]
O
This bus provides the following MSI address, data, and enabled signals:
■
msi_intf[81]
: Master enable
■
msi_intf[80
}: MSI enable
■
msi_intf[79:64]
: MSI data
■
msi_intf[63:0]
: MSI address
msix_intf[79:0]
O
This bus provides the following MSI address, data, and enabled signals:
■
msix_intf[79:64]
: MSI-X control register
■
msix_intf[63:32
}: MSI-X PBA Offset/BIR
■
msix_intf[31:0]
: MSI-X PBA Table Offset/BIR
Intx_inf[1]
I
IntxReq_i. Legacy interrupt request.
Intx_inf[0]
O
IntxAck_o. Legacy interrupt acknowledge.
Table 6–11. Interrupt Signals for Root Ports
Signal
I/O
Description
int_status[3:0]
O
These signals drive legacy interrupts to the Application Layer as follows:
■
int_status[0]: interrupt signal A
■
int_status[1]: interrupt signal B
■
int_status[2]: interrupt signal C
■
int_status[3]: interrupt signal D
serr_out
O
System Error: This signal only applies to Root Port designs that report each system error
detected, assuming the proper enabling bits are asserted in the
Root Control
register
and the
Device Control
register. If enabled,
serr_out
is asserted for a single clock
cycle when a system error occurs. System errors are described in the
3.0
in the
Root Control
register.