SLXT973QC Cortina Systems Inc, SLXT973QC Datasheet - Page 60

• Manufacturer Part Number: SLXT973QC
• Manufacturer: Cortina Systems Inc

Specifications of SLXT973QC

• Lead Free Status / Rohs Status: Not Compliant

LXT973 Transceiver
Datasheet
249426, Revision 6.0
13 July 2007
9.0
Cortina Systems
Fiber Interface
The fiber ports of the LXT973 Transceiver are designed to connect to common industry
standard fiber modules. The fiber ports incorporate LVPECL receivers and drivers,
allowing for seamless integration. The LXT973 Transceiver provides a separate pin for the
signal detect function. If designers wish to implement this feature, they need to provide a
separate signal for this function. If the signal quality starts to degrade, this pin is
essentially used to detect a remote fault condition and signals it accordingly. Loss of
signal quality also blocks any fiber data from being received and causes a loss of link.
The remote fault code consists of 84 consecutive ones followed by a single zero. This
pattern must be repeated at least three times. The LXT973 Transceiver transmits the
remote fault code a minimum of three times if all the following conditions are true:
The remote fault (Register bit 1.4) is set when the LXT973 Transceiver is either actively
transmitting a remote fault or if the LXT973 Transceiver has received a remote fault from
its link partner. The transmitted remote fault can come from the above conditions if auto-
negotiation is not enabled. If auto-negotiation is enabled, the transmitted remote fault
condition is indicated by Register bit 4.13 in the Auto-Negotiation Advertisement Register.
Likewise, a remote fault can be set by the LXT973 Transceiver link partner in two ways. If
auto-negotiation is enabled, Register bit 5.13 is set in the Auto-Negotiation Link Partner
Ability Register. If auto-negotiation is disabled, the remote fault condition is set by the
remote fault code being received on the fiber inputs.
A register bit has been provided that either selects normal, unscrambled fiber data, or
scrambles the transmitted fiber data (Register bit 26.10).
When in loopback mode, the remote fault condition is not transmitted.
®
1. Signal Detect indicates no signal
2. Far End Fault Enable bit (Register bit 16.2 Test Register) is set
3. Auto-negotiation is not enabled
4. Fiber mode is selected
LXT973 10/100 Mbps Dual-Port Fast Ethernet PHY Transceiver
9.0 Fiber Interface
Page 60