Embedian, Inc.
46
SMARC-iMX8MM Computer on Module User’s Manual
v. 1.2
2.1.8.1.
Gigabit
LAN
Signals
The
table
below
shows
the
Gigabit
LAN
related
signals.
Edge
Golden
Finder
Signal
Name
Direction
Type
Tolerance
Description
G
GBE_MDI0
‐
Bi
‐
Dir
GBE_MDI
Bi
‐
directional
transmit/receive
pair
0
to
magnetics
(Media
Dependent
Interface)
G
GBE_MDI1
‐
Bi
‐
Dir
GBE_MDI
Bi
‐
directional
transmit/receive
pair
1
to
magnetics
(Media
Dependent
Interface)
G
GBE_MDI2
‐
Bi
‐
Dir
GBE_MDI
Bi
‐
directional
transmit/receive
pair
2
to
magnetics
(Media
Dependent
Interface)
G
GBE_MDI3
‐
Bi
‐
Dir
GBE_MDI
Bi
‐
directional
transmit/receive
pair
3
to
magnetics
(Media
Dependent
Interface)
GBE_100#
Output
OD
CMOS
3.3V
Link
Speed
Indication
LED
for
100Mbps
Could
be
able
to
sink
24mA
or
more
Carrier
LED
current
GBE_1000#
Output
OD
CMOS
3.3V
Link
Speed
Indication
LED
for
1000Mbps
Could
be
able
to
sink
24mA
or
more
Carrier
LED
current
GBE_LINK_ACK#
Output
OD
CMOS
3.3V
Link
/
Activity
Indication
LED
Driven
low
on
Link
(10,
100
or
1000
mbps)
Blinks
on
Activity
Could
be
able
to
sink
24mA
or
more
Carrier
LED
current
GBE_CTREF
Output
Reference
Voltage
Center
‐
Tap
reference
voltage
for
GBE0
Carrier
board
Ethernet
magnetic
(not
required
by
the
Module
GBE
PHY)