Data Sheet

Ethernet Controller I210 —Interconnects
112
Note: If link is disconnected or auto-negotiation is re-initiated, then the LTRC.EEEMS_EN bit is
cleared by hardware. The bit should be set to 1b by software following re-execution of an EEE
LLDP negotiation.
Figure 3-15 shows the format of the EEE TLV, meaning of the various TLV parameters can be found in
IEEE802.3az clause 78 and clause 79.
3.7.7.5 Programming the I210 for EEE Operation
To activate EEE support when operating in internal PHY mode (CTRL_EXT.LINK_MODE = 00b), software
should program the following fields to enable EEE on the LAN port:
1. IPCNFG register (refer to Section 8.27.1) if default EEE advertised auto-negotiation values need to
be modified.
2. Set the EEER.TX_LPI_EN and EEER.RX_LPI_EN bits (refer to Section 8.25.12) to 1b to enable EEE
LPI support on Tx and Rx paths, respectively, if the result of auto-negotiation at the specified link
speed enables entry to LPI.
3. Set the EEER.LPI_FC bit (refer to Section 8.25.12) if required to enable a move into the EEE Tx LPI
state for the pause duration when a link partner sends a XOFF flow control packet even if internal
transmit buffer is not empty and transmit descriptors are available.
4. Update EEER.Tw_system field (refer to Section 8.25.12) with the new negotiated transmit T
w
time
after completing EEE LLDP negotiation.
5. Following the EEE LLDP negotiation program, the LTRMAXV register (refer to Section 8.25.10) with
a value of:
LTRMINV =< LTRMAXV <= LTRMINV + negotiated Receive T
w
Time.
Figure 3-15. EEE LLDP TLV