Intel PCI-X manual Receive Configuration Word Register1, Rxcw 00180h R

Register Descriptions

Field	Bit(s)	Initial	Description
		Value
			Transmit Config Control bit
			0b = Transmit data/idle
TxConfig	30	0b	1b = Transmit /C/ ordered sets
			Setting the TxConfig bit causes transmission of /C/ ordered set in
			a software controlled Auto-Negotiation process
			(TXCW.ANE=0b).
			Auto-Negotiation Enable.
			1b = Enable the hardware Auto-Negotiation state machine.
			0b = Disable the hardware Auto-Negotiation state machine.
			This bit has the same function as bit 0.12 defined in sub-clause
			22.2.4.1.4 of the 802.3z standard. Since this bit is a “static”
			value, a pulse is generated by hardware in response to writing
			this bit with a 1b. This pulse is used to restart the Auto-
ANE	31	0b	Negotiation state machine.
			When ANE is set, a transition from loss of synchronization to
			synchronized state restarts the Auto-Negotiation as well.
			If ANE is cleared, then the Ethernet controller is performing
			software Auto-Negotiation. In that case TxConfig and
			TxConfigWord are used to negotiate with the link partner.
			The ANE is loadable from the EEPROM upon power up or chip
			reset.

Note: Careful attention to the IEEE 802.3z standard is required in order to meet specified timing requirements for timing during a software negotiated link.

13.4.14Receive Configuration Word Register1

RXCW (00180h; R)

This register has meaning only in TBI/internal SerDes mode of operation. The RXCW register records the partner abilities and provides indications about its Auto-Negotiation status.

The contents of this register depend on the state of TXCW.ANE. If ANE is set, then this register records the 16-bit defined in IEEE 802.3z. When performing software Auto-Negotiation, software should look for RXCW.ANC. When RXCW.ANC is set, the contents of RXCW.RxConfigWord are valid, when RXCW.ANC is cleared, then the content of this register is undefined.

Note: While in internal SerDes mode (82546GB/EB and 82545GM/EM only), software might be required to inspect or monitor the results of RXCW to generate a link up/down indication.

1.Not applicable to the 82541xx, 82547GI/EI, or 82540EP/EM.

Software Developer’s Manual 283