<s>
A	O
unified	O
reservation	B-General_Concept
station	I-General_Concept
,	O
also	O
known	O
as	O
unified	B-General_Concept
scheduler	I-General_Concept
,	O
is	O
a	O
decentralized	O
feature	O
of	O
the	O
microarchitecture	B-General_Concept
of	O
a	O
CPU	B-General_Concept
that	O
allows	O
for	O
register	B-Architecture
renaming	I-Architecture
,	O
and	O
is	O
used	O
by	O
the	O
Tomasulo	B-General_Concept
algorithm	I-General_Concept
for	O
dynamic	B-General_Concept
instruction	I-General_Concept
scheduling	I-General_Concept
.	O
</s>
<s>
Reservation	B-General_Concept
stations	I-General_Concept
permit	O
the	O
CPU	B-General_Concept
to	O
fetch	O
and	O
re-use	O
a	O
data	O
value	O
as	O
soon	O
as	O
it	O
has	O
been	O
computed	O
,	O
rather	O
than	O
waiting	O
for	O
it	O
to	O
be	O
stored	O
in	O
a	O
register	O
and	O
re-read	O
.	O
</s>
<s>
When	O
instructions	O
are	O
issued	O
,	O
they	O
can	O
designate	O
the	O
reservation	B-General_Concept
station	I-General_Concept
from	O
which	O
they	O
want	O
their	O
input	O
to	O
read	O
.	O
</s>
<s>
Implicitly	O
register	B-Architecture
renaming	I-Architecture
solves	O
WAR	O
and	O
WAW	O
hazards	O
.	O
</s>
<s>
In	O
Tomasulo	B-General_Concept
's	I-General_Concept
algorithm	I-General_Concept
,	O
instructions	O
are	O
issued	O
in	O
sequence	O
to	O
Reservation	B-General_Concept
Stations	I-General_Concept
which	O
buffer	O
the	O
instruction	O
as	O
well	O
as	O
the	O
operands	O
of	O
the	O
instruction	O
.	O
</s>
<s>
If	O
the	O
operand	O
is	O
not	O
available	O
,	O
the	O
Reservation	B-General_Concept
Station	I-General_Concept
listens	O
on	O
a	O
Common	O
Data	O
Bus	O
for	O
the	O
operand	O
to	O
become	O
available	O
.	O
</s>
<s>
When	O
the	O
operand	O
becomes	O
available	O
,	O
the	O
Reservation	B-General_Concept
Station	I-General_Concept
buffers	O
it	O
,	O
and	O
the	O
execution	O
of	O
the	O
instruction	O
can	O
begin	O
.	O
</s>
<s>
Functional	O
Units	O
(	O
such	O
as	O
an	O
adder	O
or	O
a	O
multiplier	O
)	O
,	O
each	O
have	O
their	O
own	O
corresponding	O
Reservation	B-General_Concept
Stations	I-General_Concept
.	O
</s>
<s>
The	O
output	O
of	O
the	O
Functional	O
Unit	O
connects	O
to	O
the	O
Common	O
Data	O
Bus	O
,	O
where	O
Reservation	B-General_Concept
Stations	I-General_Concept
are	O
listening	O
for	O
the	O
operands	O
they	O
need	O
.	O
</s>
