
LU3X32FT Two-Port 3 V 10/100
Ethernet Transceiver TX/FX
Preliminary Data Sheet
July 2000
6
Lucent Technologies Inc.
Pin Descriptions
Table 1. Twisted-Pair Magnetic Interface
Table 2. Fiber-Optic Transceiver Interface
Note: Many of these signals are dual-function pins. During reset, these pins may be pulled up or down (as shown in Figure 5) to configure
various options. The secondary function is shown in smaller
print and described in Table 8.
Table 3. Twisted-Pair Transceiver Control
Table 4. MII Interface
Pin No.
22, 17
23, 16
Pin Name
TPTX+[1:0]
TPTX–[1:0]
I/O
O
Pin Description
Twisted-Pair Transmit Driver Pairs
. These pins are
used to send 100Base-T MLT-3 signals or 10Base-T
Manchester signals across UTP cable.
Twisted-Pair Receive Pair
. These pins receive
100Base-T MLT-3 data or 10Base-T Manchester data
from the UTP cable.
32, 7
33, 6
TPRX+[1:0]
TPRX–[1:0]
I
Pin No.
25, 14
26, 13
Pin Name
FOTX+[1:0]
FOTX–[1:0]
I/O
O
Pin Description
Fiber-Optic Transmit Driver Pair
. These pins are used
to transmit differential PECL level NRZI data to a fiber-
optic transceiver.
Fiber-Optic Receive Pair
. These pins are used to
receive differential PECL level NRZI data from a fiber-
optic transceiver.
Fiber-Optic Signal Detect Differential Input Pair
.
While operating in fiber mode, these pins are used to
detect whether or not the fiber-optic receive pairs are
receiving valid signal levels. See Table 8 for SRL10 and
RPTR10CLK desscriptions. If fiber and serial 10 modes
are not being used, tie all these pins low.
41, 126
40, 127
FORX+[1:0]
FORX–[1:0]
I
38, 1
39, 128
FOSD+
/SRL10
[1:0]
FOSD–/
RPTR10CLK
[1:0]
I
Pin No.
36, 3
Pin Name
REF100[1:0]
I/O
I
Pin Description
Reference Pin for 100 Mbits/s Twisted-Pair Driver
.
The value of the connected resistor is 301
.
Reference Pin for 10 Mbits/s Twisted-Pair Driver
. The
value of the connected resistor is 4.64 k
.
37, 2
REF10[1:0]
I
Pin No.
86, 81
87, 80
88, 79
89, 78
90, 77
91, 76
92, 75
97, 70
98, 69
99, 68
Pin Name
RXDV[1:0]
RXER[1:0]
RXD3[1:0]
RXD2[1:0]
RXD1[1:0]
RXD0[1:0]
RXCLK[1:0]
TXEN[1:0]
TXER[1:0]
TXD3[1:0]
I/O
O
O
O
O
O
O
O
I
I
I
Pin Description
Receive Data Valid
.
Receive Error
.
Receive Data[3]
.
Receive Data[2]
.
Receive Data[1]
.
Receive Data[0]
.
Receive Clock
.
Transmit Enable
.
Transmit Error
.
Transmit Data[3]
.