Multi-Function Support - Altera Cyclone V User Manual

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Multi-Function Support

The Cyclone V Hard IP for PCI Express supports up to eight functions for Endpoints.
You set up the each function under the
editor. You can configure Cyclone V devices to include both Native and Legacy
Endpoints. Each function replicates the Configuration Space Registers, including logic
for Tag Tracking and Error detection.
Because the Configuration Space is replicated for each function, some Configuration
Space Register settings may conflict. Arbitration logic resolves differences when
settings contain different values across multiple functions. The arbitration logic
implements the rules for resolving conflicts as specified in the
Specification
features:
■ Link Control settings
■ ECRC generation and checking
Error detection and logging for non-function-specific errors
■
■ Error message collapsing
■ Maximum payload size (All functions use the largest specified maximum payload
setting.)
■ Interrupt message collapsing
You can access the Configuration Space Registers for the active function using the
LMI interface. In Root Port mode, you can also access the Configuration Space
Registers using a Configuration Type TLP. Refer to
Content" on page 6–1
Cyclone V Hard IP for PCI Express
2.0. Examples of settings that require arbitration include the following
for more information about the Configuration Space Registers.
Chapter 4: IP Core Architecture
Port Functions heading in the parameter
PCI Express Base
"Configuration Space Register
November 2011 Altera Corporation
Multi-Function Support