<s>
The	O
Motorola	B-Device
68040	I-Device
(	O
"	O
sixty-eight-oh-forty	O
"	O
)	O
is	O
a	O
32-bit	O
microprocessor	B-Architecture
in	O
the	O
Motorola	B-Device
68000	I-Device
series	I-Device
,	O
released	O
in	O
1990	O
.	O
</s>
<s>
It	O
is	O
the	O
successor	O
to	O
the	O
68030	B-Device
and	O
is	O
followed	O
by	O
the	O
68060	B-General_Concept
,	O
skipping	O
the	O
68050	O
.	O
</s>
<s>
In	O
keeping	O
with	O
general	O
Motorola	O
naming	O
,	O
the	O
68040	B-Device
is	O
often	O
referred	O
to	O
as	O
simply	O
the	O
'	O
040	B-Device
(	O
pronounced	O
oh-four-oh	O
or	O
oh-forty	O
)	O
.	O
</s>
<s>
The	O
68040	B-Device
was	O
the	O
first	O
680x0	B-Device
family	I-Device
member	O
with	O
an	O
on-chip	O
Floating-Point	B-General_Concept
Unit	I-General_Concept
(	O
FPU	B-General_Concept
)	O
.	O
</s>
<s>
It	O
thus	O
included	O
all	O
of	O
the	O
functionality	O
that	O
previously	O
required	O
external	O
chips	O
,	O
namely	O
the	O
FPU	B-General_Concept
and	O
Memory	B-General_Concept
Management	I-General_Concept
Unit	I-General_Concept
(	O
MMU	B-General_Concept
)	O
,	O
which	O
was	O
added	O
in	O
the	O
68030	B-Device
.	O
</s>
<s>
It	O
also	O
had	O
split	O
instruction	O
and	O
data	B-General_Concept
caches	I-General_Concept
of	O
4	O
kilobytes	O
each	O
.	O
</s>
<s>
It	O
was	O
fully	O
pipelined	B-General_Concept
,	O
with	O
six	O
stages	O
.	O
</s>
<s>
Versions	O
of	O
the	O
68040	B-Device
were	O
created	O
for	O
specific	O
market	O
segments	O
,	O
including	O
the	O
68LC040	O
,	O
which	O
removed	O
the	O
FPU	B-General_Concept
,	O
and	O
the	O
68EC040	O
,	O
which	O
removed	O
both	O
the	O
FPU	B-General_Concept
and	O
MMU	B-General_Concept
.	O
</s>
<s>
Motorola	O
had	O
intended	O
the	O
EC	O
variant	O
for	O
embedded	O
use	O
,	O
but	O
embedded	O
processors	O
during	O
the	O
68040	B-Device
's	O
time	O
did	O
not	O
need	O
the	O
power	O
of	O
the	O
68040	B-Device
,	O
so	O
EC	O
variants	O
of	O
the	O
68020	B-Device
and	O
68030	B-Device
continued	O
to	O
be	O
common	O
in	O
designs	O
.	O
</s>
<s>
25MHz	O
and	O
33MHz	O
grades	O
featured	O
across	O
the	O
whole	O
line	O
,	O
but	O
until	O
around	O
2000	O
the	O
40MHz	O
grade	O
was	O
only	O
for	O
the	O
"	O
full	O
"	O
68040	B-Device
.	O
</s>
<s>
A	O
planned	O
50MHz	O
grade	O
was	O
canceled	O
after	O
it	O
exceeded	O
the	O
thermal	B-General_Concept
design	I-General_Concept
envelope	I-General_Concept
.	O
</s>
<s>
In	O
Apple	B-Device
Macintosh	I-Device
computers	I-Device
,	O
the	O
68040	B-Device
was	O
introduced	O
in	O
the	O
Macintosh	B-Device
Quadra	I-Device
,	O
which	O
was	O
named	O
for	O
the	O
chip	O
.	O
</s>
<s>
The	O
fastest	O
68040	B-Device
processor	O
was	O
clocked	O
at	O
40MHz	O
and	O
it	O
was	O
used	O
only	O
in	O
the	O
Quadra	O
840AV	O
.	O
</s>
<s>
The	O
more	O
expensive	O
models	O
in	O
the	O
(	O
short-lived	O
)	O
Macintosh	B-Device
Centris	I-Device
line	O
also	O
used	O
the	O
68040	B-Device
,	O
while	O
the	O
cheaper	O
Quadra	O
,	O
Centris	O
and	O
Macintosh	B-Device
Performa	I-Device
used	O
the	O
68LC040	O
.	O
</s>
<s>
The	O
68040	B-Device
was	O
also	O
used	O
in	O
other	O
personal	B-Device
computers	I-Device
,	O
such	O
as	O
the	O
Amiga	B-Device
4000	I-Device
and	O
Amiga	B-Device
4000T	I-Device
,	O
as	O
well	O
as	O
a	O
number	O
of	O
workstations	B-Device
,	O
Alpha	O
Microsystems	O
servers	O
,	O
the	O
HP	O
9000/400	O
series	O
,	O
NCR	O
Corporation	O
's	O
TOWER	O
32/750	O
,	O
32/825	O
and	O
32/850	O
,	O
Apollo	O
Computer	O
's	O
DN5500	B-Device
,	O
and	O
later	O
versions	O
of	O
the	O
NeXT	O
computer	O
.	O
</s>
<s>
The	O
68040	B-Device
processor	O
is	O
used	O
in	O
the	O
flight	O
management	O
computers	O
(	O
FMC	O
)	O
aboard	O
many	O
Boeing	O
737	O
aircraft	O
,	O
including	O
all	O
Next	O
Generation	O
and	O
MAX	O
models	O
.	O
</s>
<s>
The	O
68040	B-Device
ran	O
into	O
the	O
transistor	O
budget	O
limit	O
early	O
in	O
design	O
.	O
</s>
<s>
While	O
the	O
MMU	B-General_Concept
did	O
not	O
take	O
many	O
transistors	O
—	O
indeed	O
,	O
having	O
it	O
on	O
the	O
same	O
die	O
as	O
the	O
CPU	O
actually	O
saved	O
on	O
transistors	O
—	O
the	O
FPU	B-General_Concept
certainly	O
did	O
.	O
</s>
<s>
Motorola	O
's	O
68882	B-General_Concept
external	O
FPU	B-General_Concept
was	O
known	O
as	O
a	O
very	O
high	O
performance	O
unit	O
and	O
Motorola	O
did	O
not	O
wish	O
to	O
risk	O
integrators	O
using	O
the	O
"	O
LC	O
"	O
version	O
with	O
a	O
68882	B-General_Concept
instead	O
of	O
the	O
more	O
profitable	O
full	O
"	O
RC	O
"	O
unit	O
.	O
</s>
<s>
(	O
For	O
information	O
on	O
Motorola	O
's	O
multiprocessing	O
model	O
with	O
the	O
680x0	B-Device
series	O
,	O
see	O
Motorola	B-Device
68020	I-Device
.	O
)	O
</s>
<s>
The	O
FPU	B-General_Concept
in	O
the	O
68040	B-Device
was	O
thus	O
made	O
incapable	O
of	O
IEEE	O
transcendental	O
functions	O
,	O
which	O
had	O
been	O
supported	O
by	O
both	O
the	O
68881	B-General_Concept
and	O
68882	B-General_Concept
and	O
were	O
used	O
by	O
the	O
popular	O
fractal	O
generating	O
software	O
of	O
the	O
time	O
and	O
little	O
else	O
.	O
</s>
<s>
The	O
Motorola	O
floating	O
point	O
support	O
package	O
(	O
FPSP	O
)	O
emulated	B-Application
these	O
instructions	O
in	O
software	O
under	O
interrupt	O
.	O
</s>
<s>
Heat	O
was	O
always	O
a	O
problem	O
throughout	O
the	O
68040	B-Device
's	O
life	O
.	O
</s>
<s>
While	O
it	O
delivered	O
over	O
four	O
times	O
the	O
per-clock	O
performance	O
of	O
the	O
68020	B-Device
and	O
68030	B-Device
,	O
the	O
chip	O
's	O
complexity	O
and	O
power	O
requirements	O
came	O
from	O
a	O
large	O
die	O
and	O
large	O
caches	B-General_Concept
.	O
</s>
<s>
Overclocking	B-Application
enthusiasts	O
reported	O
success	O
reaching	O
50MHz	O
using	O
a	O
100MHz	O
oscillator	O
instead	O
of	O
an	O
80MHz	O
part	O
and	O
the	O
then	O
novel	O
technique	O
of	O
adding	O
oversized	O
heat	O
sinks	O
with	O
fans	O
.	O
</s>
<s>
The	O
68040	B-Device
offered	O
the	O
same	O
features	O
as	O
the	O
Intel	B-General_Concept
80486	I-General_Concept
,	O
but	O
on	O
a	O
clock-for-clock	O
basis	O
could	O
significantly	O
outperform	O
the	O
Intel	O
chip	O
in	O
integer	O
and	O
floating	O
point	O
instructions	O
.	O
</s>
<s>
The	O
68EC040	O
is	O
a	O
version	O
of	O
the	O
Motorola	B-Device
68040	I-Device
microprocessor	B-Architecture
,	O
intended	O
for	O
embedded	O
controllers	O
(	O
EC	O
)	O
.	O
</s>
<s>
It	O
differs	O
from	O
the	O
68040	B-Device
in	O
that	O
it	O
has	O
neither	O
an	O
FPU	B-General_Concept
nor	O
an	O
MMU	B-General_Concept
.	O
</s>
<s>
The	O
68EC040	O
was	O
used	O
in	O
Cisco	O
switch	O
Supervisor	B-Device
Engine	I-Device
I	I-Device
that	O
is	O
the	O
heart	O
of	O
models	O
2900	O
,	O
2948G	O
,	O
2980G	O
,	O
4000	O
,	O
4500	O
,	O
5000	O
,	O
5500	O
,	O
6000	O
,	O
6500	O
and	O
7600	O
.	O
</s>
<s>
The	O
68LC040	O
is	O
a	O
low	O
cost	O
version	O
of	O
the	O
Motorola	B-Device
68040	I-Device
microprocessor	B-Architecture
with	O
no	O
FPU	B-General_Concept
.	O
</s>
<s>
Although	O
the	O
CPU	O
now	O
fits	O
into	O
a	O
feature	O
chart	O
more	O
like	O
the	O
Motorola	B-Device
68030	I-Device
,	O
it	O
continues	O
to	O
include	O
the	O
68040	B-Device
's	O
caches	B-General_Concept
and	O
pipeline	B-General_Concept
and	O
is	O
thus	O
significantly	O
faster	O
than	O
the	O
68030	B-Device
.	O
</s>
<s>
Some	O
mask	O
revisions	O
of	O
the	O
68LC040	O
contained	O
a	O
bug	B-Error_Name
that	O
prevents	O
the	O
chip	O
from	O
operating	O
correctly	O
when	O
a	O
software	O
FPU	B-General_Concept
emulator	B-Application
is	O
used	O
.	O
</s>
<s>
According	O
to	O
Motorola	O
's	O
errata	O
,	O
any	O
chip	O
with	O
a	O
mask	O
set	O
2E71M	O
or	O
later	O
does	O
not	O
contain	O
the	O
bug	B-Error_Name
.	O
</s>
<s>
The	O
buggy	O
revisions	O
are	O
typically	O
found	O
in	O
68LC040-based	O
Apple	B-Device
Macintosh	I-Device
computers	I-Device
.	O
</s>
<s>
The	O
68040	B-Device
cannot	O
update	O
its	O
microcode	O
in	O
the	O
manner	O
of	O
modern	O
x86	O
chips	O
.	O
</s>
<s>
This	O
means	O
that	O
the	O
only	O
way	O
to	O
use	O
software	O
that	O
requires	O
floating-point	O
functionality	O
is	O
to	O
replace	O
the	O
buggy	O
68LC040	O
with	O
a	O
later	O
revision	O
,	O
or	O
a	O
full	O
68040	B-Device
.	O
</s>
