Xilinx 1000BASE-X - Manual (Page 123)

Ethernet 1000BASE-X PCS/PMA or SGMII v9.1 www.xilinx.com 123
UG155 March 24, 2008
Management Registers R
Registers 2 and 3: PHY Identifiers
1.4 Remote Fault 1 = Remote fault condition detected
0 = No remote fault condition detected
Read only
Self-
clearing
on read
0
1.3 Auto- Negotiation
Ability Always returns a ‘1’ for this bit to indicate
that the PHY is capable of Auto-
Negotiation. Returns 1 1
1.2 Link Status 1 1 = Link is up
0 = Link is down
Latches '0' if Link Status goes down.
Clears to current Link Status on read.
See table note for Link Status behavior.
Read only
Self
clearing
on read
0
1.1 Jabber Detect Always returns a ‘0’ for this bit since
Jabber Detect is not supported. Returns 0 0
1.0 Extended Capability Always returns a ‘0’ for this bit since no
extended register set is supported. Returns 0 0
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.
Table 9-4: Status Register (Register 1) (Continued)
Bit(s) Name Description Attributes
Default
Value
Registers 2 and 3: PHY Identifiers
ORGANIZE UNIQ
UE ID
15 0
Reg 2
15 0
Reg 3
ORGANIZE UNIQ
UE ID
10 9 4 3
MA
UF
A
CTURER
MODEL NO REVISION NO