<s>
An	O
Embedded	B-Architecture
Controller	I-Architecture
(	O
EC	O
)	O
is	O
a	O
microcontroller	B-Architecture
in	O
computers	O
that	O
handles	O
various	O
system	O
tasks	O
.	O
</s>
<s>
Now	O
it	O
is	O
usually	O
merged	O
with	O
Super	B-Device
I/O	I-Device
,	O
especially	O
on	O
mobile	O
platforms	O
(	O
such	O
as	O
laptop	O
)	O
.	O
</s>
<s>
An	O
embedded	B-Architecture
controller	I-Architecture
can	O
have	O
the	O
following	O
tasks	O
:	O
</s>
<s>
As	O
a	O
core	O
system	O
component	O
,	O
the	O
embedded	B-Architecture
controller	I-Architecture
is	O
always	O
on	O
when	O
power	O
is	O
supplied	O
to	O
the	O
mainboard	O
.	O
</s>
<s>
To	O
communicate	O
with	O
the	O
main	O
computer	O
system	O
,	O
several	O
forms	O
of	O
communication	O
can	O
be	O
used	O
,	O
including	O
ACPI	B-Device
,	O
SMBus	B-Algorithm
,	O
or	O
shared	B-Operating_System
memory	I-Operating_System
.	O
</s>
<s>
The	O
embedded	B-Architecture
controller	I-Architecture
has	O
its	O
own	O
RAM	B-Architecture
,	O
independent	O
of	O
that	O
used	O
by	O
the	O
main	O
computer	O
system	O
,	O
and	O
often	O
its	O
own	O
flash	B-Device
ROM	I-Device
on	O
which	O
the	O
controller	O
's	O
software	O
is	O
stored	O
.	O
</s>
<s>
Many	O
BIOS	O
updates	O
also	O
include	O
upgrades	O
for	O
the	O
embedded	B-Architecture
controller	I-Architecture
firmware	O
.	O
</s>
<s>
An	O
embedded	B-Architecture
controller	I-Architecture
is	O
sometimes	O
known	O
as	O
a	O
"	O
Keyboard	O
Controller	O
BIOS	O
"	O
,	O
which	O
comes	O
from	O
the	O
fact	O
that	O
the	O
embedded	B-Architecture
controller	I-Architecture
evolved	O
from	O
the	O
keyboard	O
controller	O
and	O
often	O
still	O
is	O
used	O
as	O
a	O
keyboard	O
controller	O
.	O
</s>
<s>
Even	O
today	O
,	O
an	O
ACPI	B-Device
embedded	B-Architecture
controller	I-Architecture
communicates	O
with	O
the	O
CPU	O
by	O
using	O
the	O
same	O
I/O	O
ports	O
that	O
keyboard	O
controllers	O
used	O
in	O
the	O
past	O
.	O
</s>
<s>
Although	O
the	O
embedded	B-Architecture
controller	I-Architecture
is	O
very	O
"	O
deep	O
"	O
in	O
the	O
system	O
,	O
it	O
is	O
important	O
to	O
the	O
user	O
because	O
it	O
performs	O
functions	O
such	O
as	O
fan	B-Device
control	I-Device
and	O
thermal	O
management	O
.	O
</s>
<s>
This	O
is	O
typically	O
done	O
by	O
activating	O
a	O
fan	O
to	O
blow	O
air	O
over	O
the	O
components	O
that	O
are	O
producing	O
heat	O
;	O
the	O
fan	O
is	O
not	O
simply	O
turned	O
on	O
or	O
off	O
,	O
but	O
is	O
driven	O
at	O
high	O
speed	O
by	O
the	O
embedded	B-Architecture
controller	I-Architecture
for	O
a	O
short	O
time	O
and	O
then	O
left	O
running	O
at	O
low	O
speed	O
until	O
the	O
temperature	O
has	O
decreased	O
sufficiently	O
.	O
</s>
<s>
To	O
prevent	O
this	O
,	O
some	O
embedded	B-Architecture
controllers	I-Architecture
are	O
designed	O
to	O
run	O
the	O
fans	O
at	O
a	O
constant	O
speed	O
over	O
a	O
larger	O
range	O
of	O
temperatures	O
and	O
will	O
only	O
increase	O
fan	O
speed	O
when	O
the	O
system	O
is	O
close	O
to	O
overheating	O
.	O
</s>
<s>
To	O
change	O
the	O
fan	B-Device
control	I-Device
policy	O
,	O
updates	O
to	O
the	O
embedded	B-Architecture
controller	I-Architecture
's	O
firmware	O
are	O
usually	O
necessary	O
.	O
</s>
