
LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
112
Datasheet
Document Number: 249241
Revision Number: 010
Revision Date: 30-May-2006
AMDIX_EN
K8
I, ST, IP
Auto MDI/MDIX Enable Default.
This pin is read at startup or reset. Its value at that time is
used to set the default state of Register bit 27.9 for all ports.
These register bits can be read and overwritten after
When active (High), automatic MDI crossover (MDIX)
(regardless of segmentation) is selected for all ports. When
inactive (Low) MDIX is selected according to the MDIX pin.
CFG_1
CFG_2
CFG_3
M10,
L9,
M9
I, ST, ID
Global Port Configuration Defaults 1-3.
These pins are read at startup or reset. Their value at that
time is used to set the default state of register bits shown in
page 128 for all ports. These register bits can be read and
overwritten after startup / reset.
When operating in Hardware Control Mode, these pins
provide configuration control options for all the ports (refer
FIFOSEL1
FIFOSEL0
C1,
F1
I, ID, ST
FIFO Select <1:0>.
These pins are read at startup or reset. Their value at that
time is used to set the default state of Register bits
18.15:14 for all ports. These register bits can be read and
overwritten after startup/reset.
These pins are shared with RMII-RxER<5:4>. An external
pull-up resistor (see applications section for value) can be
used to set FIFO Select<1:0> to active while RxER<5:4>
are three-stated during hardware reset. If no pull-up is
used, the default FIFO select state is set via the internal
pull-down resistors.
LINKHOLD
B3
I, ID, ST
LINKHOLD Default. This pin is read at startup or reset. Its
value at that time is used to set the default state of Register
bit 0.11 for all ports. This register bit can be read and
overwritten after startup / reset. When High, the LXT9785/
9785E powers down all ports.
This pin is shared with RMII-RxER6. An external pull-up
resistor (see applications section for value) can be used to
set LINKHOLD active while RxER6 is three-stated during
H/W reset. If no pull-up is used, the default LINKHOLD
state is set inactive via the internal pull-down resistor.
LED Signal Descriptions
LED0_1_L
LED0_2_L
LED0_3_L
N9
P9
M8
OD, TS,
SL, IP
Port 0 LED Drivers 1-3.
These pins drive LED indicators for Port 0. Each LED can
display one of several available status conditions as
selected by the LED Configuration Register (refer to
Table 39. Intel
LXT9785 BGA15 Signal Descriptions (Sheet 5 of 7)
Symbol
BGA15 Ball
Designation
Type
Signal Description
1. Type Column Coding: I = Input, O = Output, OD = Open Drain output, ST = Schmitt Triggered input, TS =
Three-State-able output, SL = Slew-rate Limited output, IP = weak Internal Pull-up, ID = weak Internal pull-
Down.