SGMII Link State Notification (Fixed Base Page) Mode

This mode is the same as the SGMII Link State Notification mode except the Advertised Abilities register does not need to be programmed and the PCS always transmits a Configuration Ordered Set with the code word fixed at 0x4001. This mode is used for cases where auto-negotiation fails if the link partner is checking for a fixed code word due to differences in interpretation of an ambiguous section of the SGMII specifications.

In addition to the register setup for SGMII Link State Notification mode, set the alt_sgmii_an_mode field in the SGMII CFG1 register to 1.

Link Timer Setup

The following register should be setup appropriately for the correct link timer values depending on the desired operating mode. The following registers are used to configure the link timer values:
  • SGMII CFG1—Set the an_link_timeout_val field to provide a 1.6 ms timeout value in SGMII mode or 10 ms in other modes. The default value provides 10 ms assuming a 16 ns clock period for the SerDes recovered clock.
  • SGMII CFG2—Set the an_link_fail_timeout_val field to 10 ms in all modes. This number is the default value for this register assuming a 16 ns clock period for the SerDes recovered clock.

The link timers may be shortened to speed up simulations, however, the correct values must be set up in silicon for interoperability with other devices.