The external port of the core, basex_or_sgmii
(see Dynamic Switching Signal Port), selects the default standard of the core as
follows:
- Tie to logic 0 in the core instantiation. The core powers-up and comes out of a reset cycle operating in the 1000BASE-X standard.
- Tie to logic 1 in the core instantiation. The core powers-up and comes out of a reset cycle operating in the SGMII standard.
The basex_or_sgmii port of the core can be dynamically driven. In this
configuration, it is possible to drive a logical value onto the port, followed by a core
reset cycle to switch the core to the desired standard. However, it is expected that the
standard will be switched through the MDIO management registers.