Altera Arria V GZ Avalon-ST - Manual (Page 92)

Interrupts for Root Ports
Table 5-10: Interrupt Signals for Root Ports
Signal Direction Description
int_status[3:0] Output 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 Output 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
and
Device Control
registers. If enabled,
serr_out
is asserted for a single clock cycle
when a system error occurs. System errors are described in the
PCI Express Base Specification 2.1 or 3.0 in the
Root Control
register.
Related Information
PCI Express Base Specification 2.1 or 3.0
Completion Side Band Signals
The following table 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 the
errors in the Configuration Space, and automatically sends error messages in accordance with the PCI
Express Base Specification. Note that the Application Layer is responsible for sending the completion with
the appropriate completion status value for non-posted requests. Refer to Error Handling for information
on errors that are automatically detected and handled by the Hard IP.
For a description of the completion rules, the completion header format, and completion status field
values, refer to Section 2.2.9 of the PCI Express Base Specification.
5-40 Interrupts for Root Ports
UG-01127_avst
2014.12.15
Altera Corporation Interfaces and Signal Descriptions
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