Xilinx LogiCORE 1000BASE-X User Manual page 148

R
Table 9-31: SGMII Status (Register 1) (Continued)
1. When high, the link is valid: synchronization of the SGMII link has been obtained and SGMII Auto-Negotiation (if present and
148
Bit(s) Name
1.7 Unidirectional
Ability
1.6 MF Preamble
Suppression
1.5 Auto- Negotiation
Complete
1.4 Remote Fault
1.3 Auto- Negotiation
Ability
1
1.2 SGMII Link Status
1.1 Jabber Detect
1.0 Extended Capability
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.
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Chapter 9: Configuration and Status
Description
Always returns '1,' writes ignored
Always returns a '1' for this bit to indicate
that Management Frame Preamble
Suppression is supported
Ignore this bit because Auto-Negotiation
is not included.
Ignore this bit because Auto-Negotiation
is not included
Ignore this bit because Auto-Negotiation
is not included
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.
Always returns a '0' for this bit since
Jabber Detect is not supported
Always returns a '0' for this bit because no
extended register set is supported
Ethernet 1000BASE-X PCS/PMA or SGMII v9.1
Default
Attributes
Value
returns 1 1
returns 1 1
returns 1 0
returns 0 0
returns 0 0
read only 0
self
clearing
on read
returns 0 0
returns 0 0
UG155 March 24, 2008