Intel IXF1104 manual 5.1.5Copper Mode, 5.1.4.1Fiber Auto-Negotiation, 5.1.4.3Fiber Forced Mode

IXF1104 Quad-Port 10/100/1000 Mbps Ethernet Media Access Controller

When configured for fiber mode, the full set of Optical Module interface control and status signals is presented through re-use of GMII signals on a per-port basis (see Table 4.5 “Multiplexed Ball Connections” on page 57). Fiber mode supports only full-duplex Gigabit operation.

5.1.4.1Fiber Auto-Negotiation

Auto-negotiation is performed by using the “TX Config Word ($ Port_Index + 0x17)", “RX Config Word ($ Port_Index + 0x16)", and “Diverse Config Write ($ Port_Index + 0x18)". When autoneg_enable (“Diverse Config Write ($ Port_Index + 0x18)") is set, the IXF1104 performs hardware-definedauto-negotiation with the “TX Config Word ($ Port_Index + 0x17)" used as an “Auto-Negotiation Advertisement ($ Port Index + 0x64)" and the “RX Config Word ($ Port_Index + 0x16)" used as an “Auto-Negotiation Link Partner Base Page Ability ($ Port Index + 0x65)".

Note: While the MAC supports auto-negotiation functions, the IXF1104 does not automatically configure the MAC or other device blocks to be consistent with the auto-negotiation results. This configuration is done by the user and system software.

5.1.4.2Determining If Link Is Established in Auto-Negotiation Mode

A valid link is established when the AN_complete bit is set and the RX_Sync bit reports that synchronization has occurred. Both register bits are located in the “RX Config Word ($ Port_Index + 0x16)".

If the link goes down after auto-negotiation is completed, RX_Sync indicates that a loss of synchronization occurred. The IXF1104 restarts auto-negotiation and attempts to reestablish a link. Once a link is reestablished, the AN_complete bit is set and the RX_Sync bit shows that synchronization has occurred.

To manually restart auto-negotiation, bit 5 of the “Diverse Config Write ($ Port_Index + 0x18)” (AN_enable) must be de-asserted, then re-asserted.

5.1.4.3Fiber Forced Mode

The MAC fiber operation can be forced to operate at 1000 Mbps full-duplex without completion of the auto-negotiation function. In this mode, the MAC RX path must achieve synchronization with the link partner. Once achieved, the MAC TX path is enabled to allow data transmission. This forced mode is limited to operation with a link partner that operates with a full-duplex link at 1000 Mbps.

5.1.4.4Determination of Link Establishment in Forced Mode

When the IXF1104 is in forced mode operation, the “RX Config Word ($ Port_Index + 0x16)” bit 20 RX Sync indicates when synchronization occurs and a valid link establishes.

Note: The RX Sync bit indicates a loss of synchronization when the link is down.

5.1.5Copper Mode

In copper mode, the IXF1104 transmits data on the egress path of the RGMII or GMII interface, depending on the port configuration defined by the user. The copper MAC receives data on the ingress path of the RGMII or GMII interface, depending on the port configuration defined by the

76 Datasheet

Document Number: 278757

Revision Number: 007

Revision Date: March 25, 2004