<s>
Duncan	B-Architecture
's	I-Architecture
taxonomy	I-Architecture
is	O
a	O
classification	O
of	O
computer	B-General_Concept
architectures	I-General_Concept
,	O
proposed	O
by	O
Ralph	O
Duncan	O
in	O
1990	O
.	O
</s>
<s>
Duncan	O
proposed	O
modifications	O
to	O
Flynn	B-Operating_System
's	I-Operating_System
taxonomy	I-Operating_System
to	O
include	O
pipelined	O
vector	O
processes	O
.	O
</s>
<s>
Pipelined	O
vector	B-Operating_System
processors	I-Operating_System
are	O
characterized	O
by	O
pipelined	O
functional	O
units	O
that	O
accept	O
a	O
sequential	O
stream	O
of	O
array	O
or	O
vector	O
elements	O
,	O
such	O
that	O
different	O
stages	O
in	O
a	O
filled	O
pipeline	O
are	O
processing	O
different	O
elements	O
of	O
the	O
vector	O
at	O
a	O
given	O
time	O
.	O
</s>
<s>
Early	O
examples	O
of	O
register-to-register	O
architectures	O
from	O
the	O
1960s	O
and	O
early	O
1970s	O
include	O
the	O
Cray-1	B-Device
and	O
Fujitsu	O
VP-200	O
,	O
while	O
the	O
Control	O
Data	O
Corporation	O
STAR-100	B-Device
,	O
CDC	O
205	O
and	O
the	O
Texas	O
Instruments	O
Advanced	B-Device
Scientific	I-Device
Computer	I-Device
are	O
early	O
examples	O
of	O
memory-to-memory	O
vector	O
architectures	O
.	O
</s>
<s>
The	O
late	O
1980s	O
and	O
early	O
1990s	O
saw	O
the	O
introduction	O
of	O
vector	O
architectures	O
,	O
such	O
as	O
the	O
Cray	O
Y-MP/4	O
and	O
Nippon	O
Electric	O
Corporation	O
SX-3	O
that	O
supported	O
4-10	O
vector	B-Operating_System
processors	I-Operating_System
with	O
a	O
shared	O
memory	O
(	O
see	O
NEC	B-Device
SX	I-Device
architecture	I-Device
)	O
.	O
</s>
<s>
RISC-V	O
RVV	O
may	O
mark	O
the	O
beginning	O
of	O
the	O
modern	O
revival	O
of	O
Vector	B-Operating_System
processing	I-Operating_System
.	O
</s>
<s>
This	O
scheme	O
uses	O
the	O
SIMD	B-Device
(	O
single	O
instruction	O
stream	O
,	O
multiple	O
data	O
stream	O
)	O
category	O
from	O
Flynn	B-Operating_System
's	I-Operating_System
taxonomy	I-Operating_System
as	O
a	O
root	O
class	O
for	O
processor	O
array	O
and	O
associative	O
memory	O
subclasses	O
.	O
</s>
<s>
SIMD	B-Device
architectures	O
are	O
characterized	O
by	O
having	O
a	O
control	O
unit	O
broadcast	O
a	O
common	O
instruction	O
to	O
all	O
processing	O
elements	O
,	O
which	O
execute	O
that	O
instruction	O
in	O
lockstep	O
on	O
diverse	O
operands	O
from	O
local	O
data	O
.	O
</s>
