<s>
The	O
Rabbit	B-Device
2000	I-Device
is	O
a	O
high-performance	O
8-bit	O
microcontroller	B-Architecture
designed	O
by	O
Rabbit	O
Semiconductor	O
for	O
embedded	B-Architecture
system	I-Architecture
applications	O
.	O
</s>
<s>
Rabbit	O
Semiconductor	O
has	O
been	O
bought	O
by	O
Digi	B-Application
International	I-Application
,	O
which	O
is	O
since	O
selling	O
the	O
Rabbit	B-Device
microcontrollers	I-Device
and	O
hardware	O
based	O
on	O
them	O
.	O
</s>
<s>
The	O
instruction	O
set	O
is	O
based	O
on	O
the	O
original	O
Z80	B-General_Concept
microprocessor	I-General_Concept
,	O
but	O
with	O
some	O
additions	O
of	O
new	O
instructions	O
as	O
well	O
as	O
deletions	O
of	O
some	O
instructions	O
.	O
</s>
<s>
Among	O
the	O
Z80	B-General_Concept
instructions	O
missing	O
in	O
the	O
Rabbit	O
,	O
cpir	O
is	O
particularly	O
notable	O
,	O
since	O
it	O
allows	O
for	O
much	O
more	O
efficient	O
implementations	O
of	O
some	O
often-used	O
standard	O
C	O
functions	O
such	O
as	O
strlen( )	O
,	O
strnlen( )	O
and	O
memchr( )	O
.	O
</s>
<s>
According	O
to	O
the	O
Rabbit	O
documentation	O
,	O
it	O
executes	O
its	O
instructions	O
5	O
times	O
faster	O
than	O
the	O
original	O
Z80	B-General_Concept
microprocessor	I-General_Concept
,	O
that	O
is	O
,	O
similarly	O
to	O
the	O
Zilog	B-Device
eZ80	I-Device
.	O
</s>
<s>
The	O
Rabbit	O
3000	O
is	O
a	O
variant	O
of	O
the	O
Rabbit	B-Device
2000	I-Device
with	O
the	O
same	O
core	O
,	O
but	O
more	O
powerful	O
integrated	O
peripherals	O
.	O
</s>
<s>
Most	O
of	O
the	O
Rabbit	B-Device
microcontrollers	I-Device
come	O
with	O
built-in	O
flash	B-Device
memory	I-Device
and	O
SRAM	B-Architecture
.	O
</s>
<s>
The	O
Rabbit	B-Device
2000	I-Device
is	O
supported	O
by	O
the	O
free	O
(	O
GPL	O
)	O
Small	B-Application
Device	I-Application
C	I-Application
Compiler	I-Application
and	O
Z88DK	B-Device
.	O
</s>
<s>
The	O
latter	O
two	O
are	O
quite	O
incomplete	O
in	O
their	O
support	O
of	O
the	O
C	O
standard	O
,	O
and	O
their	O
Rabbit	B-Device
2000	I-Device
backends	O
are	O
no	O
longer	O
available	O
in	O
current	O
compiler	O
versions	O
.	O
</s>
