FLLXT1000BA.C4QE000 Intel, FLLXT1000BA.C4QE000 Datasheet - Page 42

• Manufacturer Part Number: FLLXT1000BA.C4QE000
• Manufacturer: Intel

Specifications of FLLXT1000BA.C4QE000

• Lead Free Status / RoHS Status: Not Compliant

LXT1000 — Gigabit Ethernet Transceiver
2.4.6.4
2.4.7
2.4.7.1
2.4.7.2
42
Both sides set for auto-negotiate
Both sides set for forced operation
One side set for auto-negotiation and the other
for forced, half-duplex
One side set for auto-negotiation and the other
for forced full-duplex
Table 21. Determining Duplex State via Parallel Detection
Configuration
Forced Operation
Forced operation can be used to establish 10 and 100 links, and 1000 links for test purposes. In this
method, auto-negotiation is disabled completely, and the link state of the LXT1000 is determined
by MII Register 0. At reset, the state of this register is determined by the Hardware Configuration
balls, and if MDIO/MDC operation is enabled, it can by updated via software at any time.
In forced operation, the user sets the link speed (10, 100, or 1000) and duplex state (full or half).
For Gigabit (1000) links, the user must explicitly designate one side as the Master and the other as
the Slave.
Note the paradox (per the Standard): If one side of the link is forced to full-duplex operation and
the other side has auto-negotiation enabled, the auto-negotiating partner parallel-detects to a half-
duplex link while the forced side operates as directed in full-duplex mode. The result is spurious,
unexpected collisions on the side configured to auto-negotiate.
Table 21
Establishing and Maintaining the Link
Once the link state is determined—via auto-negotiation, parallel detection or forced operation—the
LXT1000 and its link partner bring up the link.
1000BASE-T
For 1000BASE-T links, the LXT1000 and its link partner enter a training phase. They exchange
idle symbols and use the information gained to set their adaptive filter coefficients. These
coefficients are used to equalize the incoming signal, as well as eliminate signal impairments such
as echo and crosstalk.
Either side indicates completion of the training phase to its link partner by changing the encoding
of the idle symbols it transmits. When both sides so indicate, the link is up. Each side continues
sending idle symbols whenever it has no data to transmit. The link is maintained as long as valid
idle, data, or carrier extension symbols are received.
100BASE-TX
For 100BASE-TX links, the LXT1000 and its link partner immediately begin transmitting idle
symbols. Each side continues sending idle symbols whenever it has no data to transmit. The link is
maintained as long as valid idle symbols or data is received.
summarizes link establishment procedures.
Link is established via auto-negotiation.
No problem as long as duplex settings match.
Link is established via parallel detect.
Link is established; however, sides disagree, resulting in transmission
problems. (Forced side will be full-duplex, auto-negotiation side will be half-
duplex.)
Result
Document #: 249276
Rev. Date: 07/20/01
Revision #: 002
Datasheet