For the Custom PHY of Cyclone® V, if a unique IP is connected and used, is it necessary for the user to control and input the control codes such as COM/SKP?

Yes, the user can insert the code for control if the original IP is used. If the original IP is used, the control code is inserted by the user.
For example, if IP is used, such as PCI-Express (PCIe) or Ethernet, the control is implemented on the IP side.

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Category: Transceivers
Tool: ^Quartus® Prime
Device: ^Cyclone® V