DJLXT905LC.C2 831645 Intel, DJLXT905LC.C2 831645 Datasheet - Page 15

• Manufacturer Part Number: DJLXT905LC.C2 831645
• Manufacturer: Intel

Specifications of DJLXT905LC.C2 831645

• Lead Free Status / RoHS Status: Not Compliant

2.9
2.9.1
2.9.2
Datasheet
Document Number: 249271
Revision Number: 004
Revision Date: 19-Oct-2005
Figure 6. Collision Detection Function
Loopback Functions
Internal Loopback
The LXT905 provides a standard loopback mode, as specified in the IEEE specification for the
twisted-pair port. It also provides a forced internal loopback mode. Loopback mode operates in
conjunction with the transmit function. The LXT905 internally loops back data that the MAC
transmits, from the TXD pin, through the Manchester encoder/decoder, to the RXD pin, and
returning to the MAC.
A data collision disables standard loopback mode, clearing the RXD circuit for the TPI data. Link
fail, jabber, and full-duplex states also disable standard loopback. Loopback is always enabled
during forced internal loopback mode.
External Loopback/Full Duplex
The LXT905 also provides an external loopback test mode for system-level testing. When both
LEDC/FDE and LBK are Low, the LXT905 enables external loopback and full-duplex mode, and
disables internal loopback circuits, SQE, and collision detection. Refer to
loopback and duplex modes.
TEN=Idle +
XMIT=Disable
RXD=TXD
TPO=TXD
A
Output
TEN=Active ∗
TPI=Idle ∗
XMIT=Enable
LXT905 Universal 10BASE-T Transceiver with 3.3V Support
TEN=Active ∗
TPI=Idle
TEN=Active ∗
TPI=Active ∗
XMIT=Enable
COL=ACTIVE
TPO=TXD
Collision
RXD=TPI
A
Idle
Power On
TEN=Active ∗
TPI=Active ∗
XMIT=Enable
TEN=Idle
TPI=Active
RXD=TPI
Input
TPI=Idle
A
Table 3
for a summary of
15