<s>
Microwatt	O
is	O
an	O
open	B-License
source	I-License
soft	B-Device
processor	I-Device
core	O
originally	O
written	O
in	O
VHDL	B-Language
by	O
Anton	O
Blanchard	O
at	O
IBM	O
,	O
announced	O
at	O
the	O
OpenPOWER	B-Application
Summit	O
NA	O
2019	O
and	O
published	O
on	O
GitHub	B-Application
in	O
August	O
2019	O
.	O
</s>
<s>
It	O
adheres	O
to	O
the	O
Power	O
ISA	O
3.0	O
instruction	B-General_Concept
set	I-General_Concept
and	O
can	O
be	O
run	O
on	O
FPGA	B-Architecture
boards	I-Architecture
,	O
booting	O
Linux	B-Application
,	O
MicroPython	B-Language
and	O
Zephyr	B-Application
.	O
</s>
<s>
Microwatt	O
is	O
a	O
tiny	O
64-bit	B-Device
bi-endian	O
scalar	B-General_Concept
integer	B-General_Concept
processor	O
core	O
,	O
implementing	O
a	O
subset	O
of	O
the	O
Power	O
ISA	O
3.0	O
instruction	B-General_Concept
set	I-General_Concept
.	O
</s>
<s>
It	O
has	O
32×	O
64-bit	B-Device
general	B-General_Concept
purpose	I-General_Concept
registers	I-General_Concept
and	O
32x	O
64-bit	B-Device
floating-point	B-General_Concept
registers	O
.	O
</s>
<s>
It	O
uses	O
Wishbone	B-Architecture
for	O
the	O
memory	O
interface	O
.	O
</s>
<s>
The	O
initial	O
development	O
was	O
done	O
in	O
a	O
couple	O
of	O
months	O
,	O
included	O
the	O
entire	O
integer	B-General_Concept
processing	O
functionality	O
of	O
the	O
instruction	B-General_Concept
set	I-General_Concept
;	O
the	O
bare	O
minimum	O
to	O
make	O
it	O
compliant	O
,	O
with	O
no	O
memory	B-General_Concept
management	I-General_Concept
unit	I-General_Concept
(	O
MMU	O
)	O
and	O
no	O
floating-point	B-General_Concept
unit	I-General_Concept
.	O
</s>
<s>
Later	O
additions	O
to	O
the	O
implementation	O
includes	O
JTAG	O
debugger	O
interface	O
,	O
divider	O
instructions	O
,	O
16KB	O
instruction	O
and	O
32KB	O
data	B-General_Concept
caches	I-General_Concept
,	O
a	O
non-hypervisor-capable	O
MMU	O
,	O
pipelining	B-General_Concept
and	O
floating-point	B-General_Concept
support	O
.	O
</s>
<s>
It	O
's	O
designed	O
using	O
VHDL	B-Language
2008	O
and	O
the	O
GHDL	O
simulation	O
environment	O
.	O
</s>
<s>
A	O
sibling	O
project	O
called	O
Chiselwatt	O
is	O
another	O
open	O
processor	O
core	O
implementing	O
the	O
Power	O
ISA	O
3.0	O
instruction	B-General_Concept
set	I-General_Concept
,	O
written	O
in	O
the	O
Scala-based	O
Chisel	O
instead	O
of	O
VHDL	B-Language
.	O
</s>
<s>
Libre-SOC	B-General_Concept
–	O
A	O
libre	B-Application
system	B-Architecture
on	I-Architecture
a	I-Architecture
chip	I-Architecture
under	O
development	O
that	O
uses	O
Microwatt	O
as	O
a	O
reference	O
design	O
.	O
</s>
<s>
Kestrel	O
–	O
A	O
soft	B-Device
BMC	O
in	O
Raptor	O
Engineering	O
POWER9	O
based	O
workstations	O
.	O
</s>
<s>
It	O
is	O
the	O
first	O
processor	O
written	O
from	O
scratch	O
using	O
the	O
open	O
Power	O
ISA	O
3.0	O
,	O
and	O
is	O
released	O
by	O
the	O
OpenPOWER	B-Application
Foundation	I-Application
as	O
a	O
reference	O
design	O
.	O
</s>
<s>
The	O
project	O
started	O
as	O
a	O
demo	O
,	O
proof	O
of	O
concept	O
and	O
a	O
reference	O
implementation	O
for	O
the	O
release	O
of	O
the	O
opensource	B-License
initiative	O
regarding	O
Power	O
ISA	O
3.0	O
.	O
</s>
<s>
Microwatt	O
is	O
set	O
to	O
be	O
fabricated	B-Architecture
in	O
130	B-Algorithm
nm	I-Algorithm
by	O
Efabless	O
"	O
Open	O
MPW	O
Shuttle	O
Program	O
"	O
in	O
2021	O
.	O
</s>
