Xilinx 1000BASE-X manual Registers 2 and 3 PHY Identifiers

Management Registers

Table 9-4:Status Register (Register 1) (Continued)

R

Bit(s)	Name	Description	Attributes	Default
				Value
1.4	Remote Fault	1 = Remote fault condition detected	Read only	0
		0 = No remote fault condition detected	Self-
			clearing
			on read
1.3	Auto- Negotiation	Always returns a ‘1’ for this bit to indicate	Returns 1	1
	Ability	that the PHY is capable of Auto-
		Negotiation.
1.2	Link Status1	1 = Link is up	Read only	0
		0 = Link is down	Self
		Latches '0' if Link Status goes down.	clearing
			on read
		Clears to current Link Status on read.
		See table note for Link Status behavior.
1.1	Jabber Detect	Always returns a ‘0’ for this bit since	Returns 0	0
		Jabber Detect is not supported.
1.0	Extended Capability	Always returns a ‘0’ for this bit since no	Returns 0	0
		extended register set is supported.

1.When high, the link is valid: synchronization of the link has been obtained and Auto-Negotiation (if present and enabled) has completed.

When low, a valid link has not been established. Either link synchronization has failed or Auto-Negotiation (if present and enabled) has failed to complete.

Regardless of whether Auto-Negotiation is enabled or disabled, there can be some delay to the deassertion of this signal following the loss of synchronization of a previously successful link. This is due to the Auto-Negotiation state machine which requires that synchronization is lost for an entire link timer duration before changing state. For more information, see the 802.3 specification.

Registers 2 and 3: PHY Identifiers

Registers 2 and 3: PHY Identifiers

15

Reg 2

15		10	9
Reg 3
	UNIQUE ID	ORGANIZE

ORGANIZE

UNIQUE ID

MAUFACTURER

MODEL NO

0

4	3	0
		REVISION NO

Ethernet 1000BASE-X PCS/PMA or SGMII v9.1 www.xilinx.com 123

UG155 March 24, 2008