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Retimers Supported
Link Extension devices (retimers) is supported to interoperate with CPM4 PCIe block for link
speed of 16.0 GT/s.
Flow Control Informational Select
All combinations of cfg_fc_sel values are supported relative to Ult, refer port description
for more details.
MSIX – Additional Vectors
When configured as MSIX-internal can support up to 32 vectors per physical function compared
to 8 in Ult, vectors per function for VF and total number of vectors (2048) remains the
same.
Switch Mode
CPM4 PCIe controller can be configured as Upstream or Downstream Port of a Switch design.
Features Not Available, or Limited Usage Features
• No Example Design - There is no example design support for this release.
• There was a core clock frequency selection available in Ult for some of the
configurations which is not available in Versal CPM4.
• Legacy Interrupts cannot be supported when PASID is enabled as some of the ports are re-
purposed.
• Pipe mode is currently not supported for Versal CPM4.
• Descrambler is currently not supported for Versal CPM4.
• Some of the advanced GT Settings present in Ult devices, such as Auto RX
Equalization, form factor driver insertion loss adjustment. TX preset selection is not supported
for Versal CPM4.
• TPH capability is not supported.
Attributes
A complete list of Versal attributes is available in the Versal ACAP Register Reference (
).
Migrating to CPM5
Appendix F: Migrating
PG346 (v3.3) November 16, 2022
CPM Mode for PCI Express
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