Embedian, Inc.
58
SMARC-iMX8MM Computer on Module User’s Manual
v. 1.2
Note:
1.
The
SDIO
card
power
should
be
switched
on
the
Carrier
board
and
the
SDIO
lines
should
be
ESD
protected.
The
SMARC
Evaluation
Carrier
schematic
is
useful
as
an
implementation
reference.
2. If
SD
boot
up
function
is
required,
the
pull
‐
up
resistor
to
3.3V
of
SDIO_PWR_EN
#
should
be
4.7k
or
less.
3.
SDIO_WP
and
SDIO_CD#
are
10k
pull
up
to
3.3V
on
module.
2.1.11.1.
SDIO
Card
(4
bit)
Interface
The
Carrier
SDIO
Card
can
be
selected
as
the
Boot
Device
(See
section
4.3).
Edge
Golden
Finder
Signal
Name
Direction
Type
Tolerance
Description
SDIO_D[0:3]
Bi
‐
Dir
CMOS
3.3V
4
bit
data
path
SDIO_CMD
Bi
‐
Dir
CMOS
3.3V
Command
Line
SDIO_CK
Output
CMOS
3.3V
Clock
SDIO_WP
Input
CMOS
3.3V
Write
Protect
SDIO_CD#
Input
CMOS
3.3V
Card
Detect
SDIO_PWR_EN
Output
CMOS
3.3V
SD
Card
Power
Enable
Note:
SD
Cards
are
not
typically
available
with
a
1.8V
I/O
voltage.
The
Module
SD
Card
I/O
level
is
specified
as
3.3V
and
not
CMOS
1.8V
.
