Embedian, Inc.
161
SMARC-iMX8MM Computer on Module User’s Manual
v. 1.2
Figure
28:
Power
‐
Up
Sequence
If
the
operating
system
supports
it,
a
shutdown
sequence
can
be
initiated.
Some
systems
may
benefit
from
shutting
down
instead
of
just
removing
the
main
power
supply
as
this
allows
the
operating
system
to
take
care
of
any
housekeeping
(e.g.
bringing
mass
storage
devices
to
a
controlled
halt).
Some
operating
system
may
not
provide
the
shutdown
function.
As
it
is
not
permitted
that
a
lower
voltage
rail
is
present
when
a
higher
voltage
rail
has
been
switched
off,
the
sequence
of
shutting
down
the
peripheral
voltages
needs
to
be
considered.
The
lower
voltages
(e.g.
peripheral
3.3V)
need
to
ramp
down
before
the
higher
ones
do
(e.g.
peripheral
5V).
