<s>
RL78	B-Device
Family	O
is	O
a	O
16-bit	O
CPU	B-General_Concept
core	O
for	O
embedded	B-Architecture
microcontrollers	B-Architecture
of	O
Renesas	O
Electronics	O
introduced	O
in	O
2010	O
.	O
</s>
<s>
Although	O
it	O
has	O
eight	O
8-bit	O
registers	O
or	O
four	O
16-bit	O
register	O
pairs	O
,	O
essentially	O
all	O
arithmetic	O
operations	O
are	O
performed	O
on	O
a	O
single	O
accumulator	B-General_Concept
(	O
the	O
A	O
register	O
or	O
AX	O
register	O
pair	O
)	O
.	O
</s>
<s>
Most	O
models	O
have	O
four	O
register	B-General_Concept
banks	I-General_Concept
which	O
may	O
be	O
selected	O
quickly	O
.	O
</s>
<s>
8-bit	O
program	B-Device
status	I-Device
word	I-Device
PSW	O
.	O
</s>
<s>
This	O
includes	O
a	O
carry	B-Algorithm
flag	I-Algorithm
(	O
borrow	O
bit	O
on	O
subtract	O
)	O
,	O
auxiliary	B-Application
carry	I-Application
flag	I-Application
and	O
zero	B-Algorithm
flag	I-Algorithm
,	O
but	O
not	O
a	O
negative	B-Algorithm
flag	I-Algorithm
or	O
overflow	B-Algorithm
flag	I-Algorithm
.	O
</s>
<s>
The	O
former	O
is	O
unnecessary	O
,	O
as	O
it	O
is	O
possible	O
to	O
branch	O
on	O
the	O
most	O
significant	O
bit	O
of	O
the	O
accumulator	B-General_Concept
directly	O
,	O
but	O
the	O
lack	O
of	O
the	O
latter	O
makes	O
signed	O
comparisons	O
awkward	O
.	O
</s>
<s>
Data	O
addressing	O
is	O
mostly	O
16-bit	O
,	O
with	O
all	O
RAM	O
and	O
special	O
function	O
registers	O
located	O
in	O
the	O
high	O
64KB	O
of	O
the	O
address	B-General_Concept
space	I-General_Concept
(	O
0xF00000xFFFFF	O
)	O
,	O
and	O
data	O
accesses	O
defaulting	O
to	O
that	O
region	O
.	O
</s>
<s>
Access	O
to	O
other	O
regions	O
of	O
the	O
address	B-General_Concept
space	I-General_Concept
uses	O
an	O
"	O
ES	O
"	O
prefix	O
opcode	O
,	O
indicating	O
that	O
the	O
high	O
four	O
address	O
bits	O
should	O
come	O
from	O
a	O
special	O
"	O
extra	O
segment	O
"	O
register	O
instead	O
.	O
</s>
<s>
Code	O
addresses	O
,	O
in	O
contrast	O
,	O
default	O
to	O
the	O
low	O
portion	O
of	O
the	O
address	B-General_Concept
space	I-General_Concept
where	O
the	O
ROM	O
is	O
located	O
.	O
</s>
<s>
Unlike	O
the	O
8086	B-General_Concept
microprocessor	I-General_Concept
,	O
there	O
are	O
no	O
separate	O
near	O
and	O
far	O
return	O
instructions	O
;	O
all	O
subroutine	O
calls	O
push	O
the	O
full	O
20-bit	O
return	O
address	O
.	O
</s>
<s>
The	O
architecture	B-General_Concept
is	O
consistently	O
little-endian	O
,	O
with	O
all	O
multi-bytes	O
values	O
appearing	O
least	O
significant	O
byte	O
.	O
</s>
<s>
with	O
3-stage	O
instruction	B-General_Concept
pipelining	I-General_Concept
.	O
</s>
<s>
It	O
has	O
20-bit	O
(	O
)	O
address	B-General_Concept
space	I-General_Concept
.	O
</s>
<s>
Its	O
basic	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
is	O
succeeded	O
from	O
78K0R	O
,	O
which	O
has	O
75	O
same	O
instructions	O
out	O
of	O
80	O
.	O
</s>
<s>
RL78	B-Device
has	O
three	O
microarchitecture	B-General_Concept
variants	O
as	O
follows	O
.	O
</s>
<s>
μ-Arch	O
ALU	O
Registers	O
Instructions	O
Pipeline	O
Remark	O
Documents	O
RL78-S3	O
16-bit	O
8×	O
8-bit	O
×4	O
banks	O
81	O
(	O
75+6	O
)	O
3-stage	O
μ-arch	O
variants	O
Renesas	O
official	O
:	O
RL78-S2	O
16-bit	O
8×	O
8-bit	O
×4	O
banks	O
75	O
3-stage	O
RL78-S1	O
8-bit	O
8×	O
8-bit	O
(	O
no	O
bank	O
)	O
74	O
(	O
75-1	O
)	O
3-stage	O
78K0R	O
16-bit	O
8×	O
8-bit	O
×4	O
banks	O
80	O
(	O
75+5	O
)	O
3-stage	O
Direct	O
predecessorExtended	O
78K/0	O
Renesas	O
official	O
:	O
78K0S	O
8-bit	O
8×	O
8-bit	O
(	O
no	O
bank	O
)	O
47	O
none	O
Simplified	O
78K/0	O
Renesas	O
official	O
:	O
78K0	O
8-bit	O
8×	O
8-bit	O
×4	O
banks	O
48	O
none	O
Basic	O
78K/0	O
core	O
Renesas	O
official	O
:	O
</s>
<s>
RL78	B-Device
covers	O
wide	O
range	O
of	O
application	O
area	O
for	O
mechanical	O
system	O
controls	O
and	O
for	O
user	B-Application
interfaces	I-Application
.	O
</s>
<s>
RL78	B-Device
Family	O
is	O
divided	O
into	O
some	O
groups	O
,	O
those	O
have	O
unique	O
naming	O
rules	O
.	O
</s>
<s>
RL78	B-Device
is	O
suitable	O
for	O
consumer	O
electronics	O
,	O
such	O
as	O
major	O
appliances	O
(	O
including	O
;	O
washing	O
machines	O
,	O
clothes	O
dryers	O
,	O
dishwashers	B-Application
,	O
refrigerators	O
,	O
and	O
air	O
conditioners	O
)	O
,	O
small	O
appliances	O
(	O
including	O
;	O
power	O
tools	O
,	O
vacuum	O
cleaners	O
,	O
and	O
coffeemakers	O
)	O
,	O
and	O
medical	O
devices	O
(	O
including	O
;	O
electronic	O
toothbrushes	O
,	O
blood	O
glucose	O
meters	O
,	O
holter	O
monitors	O
)	O
.	O
</s>
<s>
It	O
is	O
also	O
used	O
for	O
factory	O
automation	O
infrastructure	O
(	O
including	O
;	O
sensors	O
,	O
gauges	O
,	O
and	O
actuators	B-Algorithm
)	O
,	O
</s>
<s>
and	O
energy	O
conservation	O
(	O
including	O
;	O
smart	B-Device
meters	I-Device
,	O
inverter	O
compressors	O
,	O
and	O
lighting	O
control	O
systems	O
)	O
.	O
</s>
<s>
For	O
automotive	O
industry	O
,	O
low-power	O
and	O
size	O
constrained	O
applications	O
are	O
ideally	O
suited	O
to	O
RL78	B-Device
's	O
automotive	O
dedicated	O
communication	O
interfaces	O
,	O
such	O
as	O
CAN	O
,	O
LIN	O
,	O
and	O
IEBus	B-General_Concept
,	O
</s>
<s>
RL78	B-Device
(	O
130nm	O
MF3	O
flash	O
process	O
)	O
was	O
the	O
first	O
new	O
MCU	O
to	O
emerge	O
from	O
the	O
new	O
Renesas	O
Electronics	O
company	O
from	O
the	O
merger	O
of	O
NEC	O
Electronics	O
and	O
Renesas	O
Technology	O
and	O
incorporated	O
the	O
features	O
of	O
the	O
NEC	O
78K0R	O
(	O
150nm	O
MF2	O
flash	O
process	O
)	O
and	O
Renesas	O
Technology	O
R8C	B-Device
microcontrollers	B-Architecture
.	O
</s>
<s>
The	O
RL78	B-Device
core	O
variants	O
include	O
the	O
S1	O
,	O
S2	O
,	O
and	O
S3	O
type	O
cores	O
which	O
evolved	O
from	O
the	O
NEC	O
78K0R	O
core	O
.	O
</s>
<s>
The	O
RL78	B-Device
was	O
developed	O
to	O
address	O
extremely	O
low	O
power	O
but	O
highly	O
integrated	O
microcontroller	B-Architecture
applications	O
,	O
to	O
this	O
end	O
the	O
core	O
offered	O
a	O
novel	O
low	O
power	O
mode	O
of	O
operation	O
called	O
“	O
snooze	O
mode	O
”	O
where	O
the	O
ADC	O
or	O
serial	B-Protocol
interface	I-Protocol
can	O
be	O
programmed	O
to	O
meet	O
specific	O
conditions	O
to	O
wake	O
the	O
device	O
from	O
the	O
extreme	O
low	O
power	O
STOP	O
mode	O
of	O
0.52uA	O
.	O
</s>
<s>
The	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
,	O
</s>
<s>
The	O
Renesas	O
CS+	O
IDE	B-Application
is	O
free	O
for	O
debug-only	O
use	O
and	O
supports	O
standard	O
ELF	O
executable	O
files	O
.	O
</s>
<s>
The	O
RL78	B-Device
ABI	O
defined	O
by	O
Renesas	O
is	O
compatible	O
with	O
IAR	O
's	O
V2	O
and	O
higher	O
compilers	O
.	O
</s>
<s>
Regarding	O
real-time	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
,	O
CMX	O
Systems	O
,	O
Inc.	O
'	O
s	O
CMX-RTX	O
,	O
Micrium	O
,	O
Inc.	O
'	O
s	O
μC/OS	B-Operating_System
-II	I-Operating_System
and	O
MicroC/OS	B-Operating_System
-III	I-Operating_System
,	O
Segger	O
Microcontroller	B-Architecture
Systems	O
 '	O
embOS	O
,	O
FreeRTOS	B-Operating_System
,	O
and	O
ChibiOS/RT	B-Operating_System
are	O
supported	O
.	O
</s>
<s>
A	O
EEPROM	O
Emulation	O
Library	O
(	O
EEL	O
)	O
is	O
also	O
available	O
for	O
the	O
data-flash	O
to	O
add	O
wear	B-Application
leveling	I-Application
and	O
robustness	O
.	O
</s>
<s>
Several	O
companies	O
provide	O
on-chip	O
debuggers	O
and	O
full-spec	O
in-circuit	B-Application
emulators	I-Application
.	O
</s>
<s>
supply	O
full-spec	O
in-circuit	B-Application
emulators	I-Application
.	O
</s>
<s>
while	O
several	O
third-parties	O
support	O
RL78	B-Device
with	O
their	O
own	O
device	O
programmers	O
.	O
</s>
<s>
RL78	B-Device
Family	O
has	O
a	O
range	O
of	O
devices	O
from	O
20pin	O
with	O
16K	O
Byte	O
flash	B-Device
memory	I-Device
to	O
128pin	O
with	O
512K	O
Byte	O
flash	B-Device
memory	I-Device
.	O
</s>
<s>
RL78/G13	O
integrates	O
a	O
+	O
/	O
-	O
1%	O
accuracy	O
on-chip	O
oscillator	O
,	O
watch	B-Application
dog	I-Application
timer	I-Application
,	O
RTC	O
,	O
power-on	B-Application
reset	I-Application
,	O
low	O
voltage	O
detection	O
,	O
26	O
channels	O
of	O
10bit	O
ADC	O
,	O
16x16	O
Multiplier	O
,	O
32/32	O
Divider	O
,	O
I2C	O
,	O
CSI/SPI	O
,	O
UART	O
,	O
LIN	O
,	O
multi-function	O
timer	O
array	O
and	O
also	O
built-in	O
IEC	O
60730	O
safety	O
support	O
in	O
hardware	O
.	O
</s>
<s>
This	O
combination	O
of	O
elements	O
enables	O
the	O
system	O
designer	O
to	O
achieve	O
high	O
performance	O
(	O
41DMIPS	O
)	O
systems	O
operating	O
at	O
very	O
low	O
power	O
levels	O
and	O
at	O
low	O
cost	O
due	O
to	O
the	O
high	O
level	O
of	O
integration	O
in	O
the	O
microcontroller	B-Architecture
.	O
</s>
<s>
Introduced	O
with	O
20	O
,	O
24	O
,	O
and	O
30-pin	O
packages	O
with	O
2	O
KB	O
to	O
16	O
KB	O
small	O
size	O
flash	B-Device
memory	I-Device
although	O
providing	O
the	O
G13	O
functionality	O
with	O
integrated	O
+	O
/	O
-	O
1%	O
24MHz	O
oscillator	O
,	O
reset	O
circuit	O
,	O
a	O
low	O
voltage	O
detection	O
circuit	O
,	O
watchdog	B-Application
timer	I-Application
,	O
data	O
flash	O
with	O
background	O
operation	O
,	O
and	O
including	O
functional	O
safety	O
,	O
on-chip	O
with	O
A/D	O
converter	O
testing	O
function	O
.	O
</s>
<s>
This	O
small	O
device	O
is	O
designated	O
for	O
use	O
as	O
a	O
sub-microcontroller	O
suitable	O
for	O
use	O
as	O
in	O
small	O
home	O
appliances	O
and	O
general	O
consumer	O
electronic	O
devices	O
.	O
</s>
<s>
In	O
2012	O
an	O
addition	O
to	O
the	O
RL78	B-Device
family	O
was	O
introduced	O
called	O
the	O
.	O
</s>
<s>
This	O
device	O
offers	O
higher	O
levels	O
of	O
integration	O
with	O
the	O
inclusion	O
of	O
additional	O
multiply	O
and	O
divide	O
and	O
multiply-accumulate	O
instructions	O
capable	O
of	O
faster	O
processing	O
than	O
the	O
RL78/G13	O
,	O
2	O
Channel	O
8-bit	O
D/A	O
,	O
2	O
Channel	O
comparator	O
,	O
and	O
timer	O
array	O
making	O
it	O
suitable	O
for	O
motor	O
control	O
applications	O
.	O
</s>
<s>
An	O
application	O
specific	O
version	O
(	O
ASSP	O
)	O
of	O
the	O
RL78	B-Device
core	O
was	O
introduced	O
in	O
2012	O
for	O
controlling	O
lighting	O
systems	O
,	O
this	O
device	O
was	O
named	O
the	O
RL78/I1A	O
.	O
</s>
<s>
Specific	O
features	O
of	O
the	O
device	O
such	O
as	O
special	O
PWM	B-Algorithm
timers	O
enable	O
fine	O
dimming	O
,	O
lighting	O
sequence	O
and	O
colour	O
temperature	O
control	O
with	O
power	O
factor	O
correction	O
of	O
the	O
power	O
supply	O
.	O
</s>
<s>
In	O
addition	O
integrated	O
communication	O
functions	O
for	O
DALI	O
,	O
DMX512	O
and	O
multiple	O
sensor	O
&	O
user	B-Application
interface	I-Application
controls	O
are	O
provided	O
.	O
</s>
<s>
Applications	O
for	O
the	O
RL78/I1A	O
include	O
:	O
building	O
automation	O
,	O
LED	O
drivers	O
,	O
lighting	O
controls	O
,	O
fluorescent	O
ballasts	O
,	O
emergency	O
lighting	O
,	O
HID	O
ballasts	O
,	O
digital	O
power	O
supplies	O
,	O
low-cost	O
inverter	O
controls	O
.	O
</s>
<s>
Entering	O
mass	O
production	O
at	O
the	O
beginning	O
of	O
2013	O
,	O
the	O
includes	O
integrated	O
LCD	B-Device
drive	O
capability	O
for	O
35	O
segments	O
x	O
8	O
or	O
39	O
segments	O
x	O
4	O
.	O
</s>
<s>
Three	O
alternative	O
LCD	B-Device
drive	O
methods	O
mat	O
be	O
enabled	O
:	O
split	O
capacitor	O
,	O
capacitive	O
charge	O
pump	O
or	O
external	O
split	O
resistor	O
.	O
</s>
<s>
With	O
the	O
split	O
capacitor	O
method	O
a	O
low	O
power	O
LCD	B-Device
drive	O
of	O
0.6uA	O
at	O
3V	O
can	O
be	O
achieved	O
.	O
</s>
<s>
The	O
RL78	B-Device
,	O
,	O
,	O
&	O
devices	O
replaced	O
the	O
original	O
devices	O
with	O
many	O
updates	O
including	O
die	O
shrink	O
,	O
faster	O
core	O
speed	O
(	O
32MHz	O
)	O
,	O
improved	O
on-chip	O
debug	O
capability	O
,	O
new	O
peripherals	O
,	O
safety	O
features	O
,	O
and	O
expanded	O
package	O
and	O
memory	O
options	O
.	O
</s>
<s>
The	O
application	O
note	O
can	O
be	O
used	O
as	O
a	O
guide	O
when	O
migrating	O
from	O
78K0R/Fx3	O
to	O
RL78/F1x	O
.	O
</s>
