Xilinx 1000BASE-X - Manual (Page 138)

138 www.xilinx.com Ethernet 1000BASE-X PCS/PMA or SGMII v9.1
UG155 March 24, 2008
Chapter 9: Configuration and Status R
1.7 Unidirectional
Ability Always returns ‘1,’ writes ignored returns 1 1
1.6 MF Preamble
Suppression Always returns a ‘1’ for this bit to indicate
that Management Frame Preamble
Suppression is supported returns 1 1
1.5 Auto- Negotiation
Complete 1 = Auto-Negotiation process completed
across SGMII link
0 = Auto-Negotiation process not
completed across SGMII link
read only 0
1.4 Remote Fault 1 = A fault on the Medium has been
detected
0 = No fault of the Medium has been
detected
read only
self
clearing
on read
0
1.3 Auto- Negotiation
Ability Always returns a ‘1’ for this bit to indicate
that the SGMII core is capable of Auto-
Negotiation returns 1 1
1.2 SGMII Link Status 1 1 = SGMII Link is up
0 = SGMII Link is down
Latches '0' if SGMII Link Status goes
down. Clears to current SGMII Link
Status on read.
See table note for SGMII 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 because no
extended register set is supported returns 0 0
1. When high, the link is valid: synchronization of the SGMII link has been obtained and SGMII Auto-Negotiation (if present and
enabled) has completed.
When low, a valid link has not been established. Either SGMII link synchronization has failed or SGMII Auto-Negotiation (if
present and enabled) has failed to complete.
Regardless of whether SGMII 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 SGMII 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 9-20: SGMII Status (Register 1) (Continued)
Bit(s) Name Description Attributes
Default
Value