<s>
Embedded	B-Application
software	I-Application
is	O
computer	O
software	O
,	O
written	O
to	O
control	O
machines	O
or	O
devices	O
that	O
are	O
not	O
typically	O
thought	O
of	O
as	O
computers	O
,	O
commonly	O
known	O
as	O
embedded	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
This	O
term	O
is	O
sometimes	O
used	O
interchangeably	O
with	O
firmware	B-Application
.	O
</s>
<s>
A	O
precise	O
and	O
stable	O
characteristic	O
feature	O
is	O
that	O
no	O
or	O
not	O
all	O
functions	O
of	O
embedded	B-Application
software	I-Application
are	O
initiated/controlled	O
via	O
a	O
human	O
interface	O
,	O
but	O
through	O
machine-interfaces	O
instead	O
.	O
</s>
<s>
Manufacturers	O
build	O
embedded	B-Application
software	I-Application
into	O
the	O
electronics	O
of	O
cars	O
,	O
telephones	O
,	O
modems	O
,	O
robots	B-Algorithm
,	O
appliances	O
,	O
toys	O
,	O
security	O
systems	O
,	O
pacemakers	B-Device
,	O
televisions	O
and	O
set-top	O
boxes	O
,	O
and	O
digital	O
watches	O
,	O
for	O
example	O
.	O
</s>
<s>
This	O
software	O
can	O
be	O
very	O
simple	O
,	O
such	O
as	O
lighting	O
controls	O
running	O
on	O
an	O
8-bit	O
microcontroller	B-Architecture
with	O
a	O
few	O
kilobytes	O
of	O
memory	O
with	O
the	O
suitable	O
level	O
of	O
processing	O
complexity	O
determined	O
with	O
a	O
Probably	O
Approximately	O
Correct	O
Computation	O
framework	O
(	O
a	O
methodology	O
based	O
on	O
randomized	B-General_Concept
algorithms	I-General_Concept
)	O
.	O
</s>
<s>
However	O
,	O
embedded	B-Application
software	I-Application
can	O
become	O
very	O
sophisticated	O
in	O
applications	O
such	O
as	O
routers	B-Protocol
,	O
optical	O
network	O
elements	O
,	O
airplanes	O
,	O
missiles	O
,	O
and	O
process	O
control	O
systems	O
.	O
</s>
<s>
Unlike	O
standard	O
computers	O
that	O
generally	O
use	O
an	O
operating	O
systems	O
such	O
as	O
macOS	B-Application
,	O
Windows	B-Application
or	O
Linux	B-Application
,	O
embedded	B-Application
software	I-Application
may	O
use	O
no	O
operating	O
system	O
.	O
</s>
<s>
When	O
they	O
do	O
use	O
one	O
,	O
a	O
wide	O
variety	O
of	O
operating	O
systems	O
can	O
be	O
chosen	O
from	O
,	O
typically	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
Code	O
for	O
embedded	B-Application
software	I-Application
is	O
typically	O
written	O
in	O
C	B-Language
or	O
C++	B-Language
,	O
but	O
various	O
high-level	B-Language
programming	I-Language
languages	I-Language
,	O
such	O
as	O
Java	B-Language
,	O
Python	B-Language
and	O
JavaScript	B-Language
,	O
are	O
now	O
also	O
in	O
common	O
use	O
to	O
target	O
microcontrollers	B-Architecture
and	O
embedded	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
Assembly	B-Language
languages	I-Language
are	O
often	O
used	O
too	O
,	O
especially	O
in	O
booting	O
and	O
interrupt	B-Application
handling	I-Application
.	O
</s>
<s>
Ada	B-Language
is	O
used	O
in	O
some	O
military	O
and	O
aviation	O
projects	O
.	O
</s>
<s>
Most	O
consumers	O
are	O
familiar	O
with	O
application	B-Application
software	I-Application
that	O
provide	O
functionality	O
on	O
a	O
computer	O
.	O
</s>
<s>
However	O
embedded	B-Application
software	I-Application
is	O
often	O
less	O
visible	O
,	O
but	O
no	O
less	O
complicated	O
.	O
</s>
<s>
Unlike	O
application	B-Application
software	I-Application
,	O
embedded	B-Application
software	I-Application
has	O
fixed	O
hardware	O
requirements	O
and	O
capabilities	O
,	O
and	O
addition	O
of	O
third-party	O
hardware	O
or	O
software	O
is	O
strictly	O
controlled	O
.	O
</s>
<s>
Embedded	B-Application
software	I-Application
needs	O
to	O
include	O
all	O
needed	O
device	B-Application
drivers	I-Application
at	O
manufacturing	O
time	O
,	O
and	O
the	O
device	B-Application
drivers	I-Application
are	O
written	O
for	O
the	O
various	O
hardware	O
devices	O
.	O
</s>
<s>
These	O
device	B-Application
drivers	I-Application
,	O
called	O
BSP	O
(	O
Board	B-Operating_System
support	I-Operating_System
package	I-Operating_System
)	O
,	O
form	O
the	O
layer	O
of	O
software	O
containing	O
hardware-specific	O
drivers	O
and	O
other	O
routines	O
that	O
allow	O
a	O
particular	O
operating	O
system	O
(	O
traditionally	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
,	O
or	O
RTOS	B-Operating_System
)	O
to	O
function	O
in	O
a	O
particular	O
hardware	O
environment	O
(	O
a	O
computer	O
or	O
CPU	O
card	O
)	O
,	O
integrated	O
with	O
the	O
RTOS	B-Operating_System
itself	O
.	O
</s>
<s>
Most	O
embedded	B-Application
software	I-Application
engineers	O
have	O
at	O
least	O
a	O
passing	O
knowledge	O
of	O
reading	O
schematics	B-Application
,	O
and	O
reading	O
data	O
sheets	O
for	O
components	O
to	O
determine	O
usage	O
of	O
registers	O
and	O
communication	O
system	O
.	O
</s>
<s>
Conversion	O
between	O
decimal	B-Application
,	O
hexadecimal	O
and	O
binary	O
is	O
useful	O
as	O
well	O
as	O
using	O
bit	B-Algorithm
manipulation	I-Algorithm
.	O
</s>
<s>
Software	O
development	O
requires	O
use	O
of	O
a	O
cross	B-Application
compiler	I-Application
,	O
which	O
runs	O
on	O
a	O
computer	O
but	O
produces	O
executable	O
code	O
for	O
the	O
target	O
device	O
.	O
</s>
<s>
Debugging	O
requires	O
use	O
of	O
an	O
in-circuit	B-Application
emulator	I-Application
,	O
and	O
debugging	O
hardware	O
such	O
as	O
JTAG	O
or	O
SWD	O
debuggers	O
.	O
</s>
<s>
These	O
space	O
requirements	O
lead	O
to	O
more	O
work	O
being	O
done	O
in	O
C	B-Language
or	O
embedded	B-Language
C++	I-Language
,	O
instead	O
of	O
C++	B-Language
.	O
</s>
<s>
Parallax	O
Propeller	O
can	O
use	O
compiled	O
BASIC	O
)	O
and	O
Java	B-Language
(	O
Java	B-Language
ME	O
Embedded	O
8.3	O
is	O
available	O
for	O
e.g.	O
</s>
<s>
ARM	B-Application
Cortex-M4	O
,	O
Cortex-M7	O
microcontrollers	B-Architecture
and	O
older	O
ARM11	O
used	O
in	O
Raspberry	B-Operating_System
Pi	I-Operating_System
and	O
Intel	B-Device
Galileo	I-Device
Gen	O
.	O
2	O
)	O
are	O
not	O
commonly	O
used	O
;	O
while	O
an	O
implementation	O
of	O
the	O
interpreted	O
Python	B-Language
3	O
language	O
MicroPython	B-Language
is	O
however	O
available	O
expressly	O
for	O
microcontroller	B-Architecture
use	O
,	O
e.g.	O
</s>
<s>
32-bit	O
ARM-based	O
(	O
such	O
as	O
BBC	O
micro:bit	O
)	O
and	O
16-bit	B-Device
PIC	B-Architecture
microcontrollers	I-Architecture
.	O
</s>
<s>
Besides	O
direct	B-General_Concept
memory	I-General_Concept
addressing	I-General_Concept
,	O
hardware	O
level	O
common	O
protocols	O
include	O
I²C	O
,	O
SPI	B-Architecture
,	O
serial	B-Protocol
ports	I-Protocol
,	O
1-Wires	O
,	O
Ethernets	O
,	O
and	O
USB	B-Protocol
.	O
</s>
<s>
Communications	O
protocols	O
designed	O
for	O
use	O
in	O
embedded	B-Architecture
systems	I-Architecture
are	O
available	O
as	O
closed	B-Application
source	I-Application
from	O
companies	O
including	O
InterNiche	B-Application
Technologies	I-Application
and	O
CMX	O
Systems	O
.	O
</s>
<s>
Open-source	B-License
protocols	O
stem	O
from	O
uIP	B-Protocol
,	O
lwip	B-Application
,	O
and	O
others	O
.	O
</s>
