SLXT973QE Cortina Systems Inc, SLXT973QE Datasheet - Page 36

• Manufacturer Part Number: SLXT973QE
• Manufacturer: Cortina Systems Inc

Specifications of SLXT973QE

• Lead Free Status / RoHS Status: Not Compliant

LXT973 Transceiver
Datasheet
249426, Revision 6.0
13 July 2007
3.7.6
3.8
3.8.1
Figure 9
Cortina Systems
Far End Fault
In fiber mode, the SDn pin monitors signal quality. If signal quality degrades beyond the
fault threshold, the fiber transceiver reports a signal quality fault condition via the SDn pin.
Loss of signal quality blocks any fiber data from being received and causes a loss of link.
If the LXT973 Transceiver detects a signal fault condition, it transmits the Far End Fault
Indication (FEFI) over the fiber link. The FEFI consists of 84 consecutive “1s” followed by
a single “0.” This pattern must be repeated at least three times. The LXT973 Transceiver
transmits the Far-End Fault code a minimum of three times if all the following conditions
are true:
100 Mbps Operation
100BASE-X Network Operations
During 100BASE-X operation, the LXT973 Transceiver transmits and receives 5-bit
symbols across the network link.
When the MAC is not actively transmitting data, the LXT973 Transceiver sends out IDLE
symbols on the line.
In 100BASE-TX mode, the device scrambles the data and transmits it to the network
using MLT-3 line code. The MLT-3 signals received from the network are de-scrambled
and decoded, and sent across the MII to the MAC.
In 100BASE-FX mode, the LXT973 Transceiver transmits and receives NRZI signals
across the LVPECL interface. An external 100BASE-FX transceiver module is required to
complete the fiber connection.
As shown in
as the LXT973 Transceiver detects the start of preamble, it transmits a J/K Start-of-Stream
Delimiter (SSD) symbol to the network. It then encodes and transmits the rest of the
packet, including the balance of the preamble, the Start-of-Frame Delimiter (SFD), packet
data, and CRC. Once the packet ends, the LXT973 Transceiver transmits the T/R End-of-
Stream Delimiter (ESD) symbol and returns to transmitting IDLE symbols.
100BASE-X Frame Format
®
Replaced by
/J/K/ code-groups
Start-of-Stream
Delimiter (SSD)
• Fiber mode is selected.
• Far End Fault Code transmission is enabled (Register bit 16.2 = 1).
• Signal Detect indicates either no signal or the receive PLL cannot lock.
• Loopback is not enabled.
LXT973 10/100 Mbps Dual-Port Fast Ethernet PHY Transceiver
P0
64-Bit Preamble
P1
(8 Octets)
P6
Figure
Delimiter (SFD)
Start-of-Frame
SFD
9, the MAC starts each transmission with a preamble pattern. As soon
DA
Address (6 Octets each)
Destination and Source
DA
SA
Figure 9
SA
Packet Length
L1
shows the structure of a standard frame packet.
(2 Octets)
L2
(Pad to minimum packet size)
D0
Data Field
D1
Dn
Frame Check Field
(4 Octets)
CRC
3.8 100 Mbps Operation
End-of-Stream Delimiter (ESD)
/T/R/ code-groups
Replaced by
InterFrame Gap / Idle Code
I0
(> 12 Octets)
IFG
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