<s>
Memory	B-Application
testers	I-Application
are	O
specialized	O
test	O
equipment	O
used	O
to	O
test	O
and	O
verify	O
memory	B-General_Concept
modules	I-General_Concept
.	O
</s>
<s>
Memory	O
module	O
testers	O
can	O
be	O
broadly	O
categorized	O
into	O
two	O
types	O
,	O
hardware	B-Architecture
memory	B-Application
testers	I-Application
and	O
software	O
diagnostic	B-Application
programs	I-Application
that	O
run	O
in	O
a	O
PC	B-Device
environment	O
.	O
</s>
<s>
Hardware	B-Architecture
memory	B-Application
testers	I-Application
have	O
more	O
sophisticated	O
and	O
comprehensive	O
test	O
features	O
built	O
into	O
the	O
tester	O
as	O
compared	O
to	O
software	O
diagnostic	O
testing	O
programs	O
.	O
</s>
<s>
Software	O
diagnostic	O
does	O
allow	O
for	O
detection	O
of	O
possible	O
problems	O
when	O
memory	B-General_Concept
modules	I-General_Concept
are	O
already	O
installed	O
on	O
the	O
computer	O
system	O
.	O
</s>
<s>
High-end	O
automatic	O
test	O
equipment	O
(	O
ATE	O
)	O
Class	O
Memory	B-Application
testers	I-Application
are	O
used	O
by	O
most	O
OEM	O
memory	O
chip	O
manufacturers	O
such	O
as	O
Samsung	O
,	O
Hyundai	O
,	O
Micron	O
…	O
etc	O
.	O
</s>
<s>
ATE	O
Class	O
Memory	B-Application
testers	I-Application
are	O
built	O
with	O
very	O
complex	O
test	O
algorithms	O
to	O
detect	O
memory	O
faults	O
during	O
the	O
final	O
stages	O
of	O
memory	O
chip	O
packaging	O
.	O
</s>
<s>
Mid-range	O
memory	B-Application
testers	I-Application
typically	O
priced	O
under	O
$26	O
,	O
000	O
,	O
and	O
are	O
commonly	O
found	O
in	O
memory	O
module	O
manufacturing	O
assembly	O
houses	O
.	O
</s>
<s>
These	O
memory	B-Application
testers	I-Application
are	O
usually	O
docked	O
onto	O
an	O
automatic	O
handling	O
system	O
for	O
high	O
volume	O
production	O
testing	O
,	O
thus	O
eliminating	O
manual	O
intervention	O
by	O
an	O
operator	O
.	O
</s>
<s>
Low-end	O
memory	B-Application
testers	I-Application
are	O
usually	O
relatively	O
low	O
cost	O
ranging	O
from	O
$1000	O
–	O
$3000	O
.	O
</s>
<s>
They	O
are	O
typically	O
used	O
by	O
the	O
service	O
industry	O
especially	O
by	O
computer	O
service	O
technicians	O
,	O
RMA	O
departments	O
,	O
memory	O
reseller/brokers/	O
and	O
wholesalers	O
for	O
verifying	O
and	O
testing	O
memory	B-General_Concept
modules	I-General_Concept
that	O
fails	O
in	O
PC	B-Device
system	O
or	O
before	O
going	O
into	O
PC	B-Device
.	O
</s>
<s>
Quality	O
and	O
features	O
of	O
this	O
range	O
of	O
memory	B-Application
testers	I-Application
varies	O
greatly	O
depending	O
on	O
the	O
manufacturer	O
.	O
</s>
<s>
A	O
good	O
memory	B-Application
tester	I-Application
is	O
built	O
with	O
features	O
comparable	O
with	O
high-end	O
ATE	O
and	O
medium	O
range	O
memory	B-Application
tester	I-Application
.	O
</s>
<s>
Memory	O
diagnostic	O
software	O
programs	O
(	O
e.g.	O
,	O
memtest86	B-Application
)	O
are	O
low-cost	O
or	O
free	O
tools	O
used	O
to	O
check	O
for	O
memory	O
failures	O
on	O
a	O
PC	B-Device
.	O
</s>
<s>
They	O
are	O
usually	O
in	O
the	O
form	O
of	O
a	O
bootable	B-Operating_System
software	O
distribution	O
on	O
a	O
floppy	B-Device
disk	I-Device
or	O
CD-ROM	B-Device
.	O
</s>
<s>
The	O
diagnostic	O
tools	O
provide	O
memory	B-Application
test	I-Application
patterns	O
which	O
are	O
able	O
to	O
test	O
all	O
system	O
memory	O
in	O
a	O
computer	O
.	O
</s>
<s>
Diagnostic	O
software	O
cannot	O
be	O
used	O
when	O
a	O
PC	B-Device
is	O
unable	O
to	O
start	B-Operating_System
due	O
to	O
memory	O
or	O
motherboard	B-Device
.	O
</s>
<s>
While	O
in	O
principle	O
a	O
test	O
program	O
could	O
report	O
its	O
results	O
by	O
sending	O
them	O
to	O
a	O
storage	O
device	O
(	O
e.g.	O
,	O
floppy	B-Device
disc	I-Device
)	O
or	O
printer	O
if	O
working	O
,	O
or	O
by	O
sound	O
signals	O
,	O
in	O
practice	O
a	O
working	O
display	O
is	O
required	O
.	O
</s>
<s>
Some	O
stronger	O
memory	B-Application
tests	I-Application
capable	O
of	O
detecting	O
subtle	O
timing	O
problems	O
are	O
implemented	O
as	O
self-modifying	B-Application
,	O
dynamically	O
self-relocating	O
and	O
potentially	O
self-destructive	O
memory	O
worms	O
called	O
worm	O
memory	B-Application
test	I-Application
(	O
or	O
worm	O
test	O
)	O
.	O
</s>
<s>
Memory	B-Application
testers	I-Application
are	O
designed	O
to	O
detect	O
two	O
types	O
of	O
faults	O
that	O
affect	O
the	O
functional	O
behavior	O
of	O
a	O
system	O
(	O
memory	O
chip	O
,	O
logic	O
chips	O
or	O
PCB	O
board	O
)	O
:	O
Non-Permanent	O
faults	O
and	O
Permanent	O
faults	O
.	O
</s>
<s>
Permanent	O
faults	O
affect	O
the	O
logic	O
values	O
in	O
the	O
system	O
permanently	O
,	O
these	O
faults	O
are	O
easier	O
to	O
detect	O
using	O
a	O
memory	B-Application
tester	I-Application
.	O
</s>
<s>
The	O
detection	O
and	O
localization	O
of	O
non-permanent	O
faults	O
are	O
extremely	O
difficult	O
with	O
a	O
memory	B-Application
tester	I-Application
.	O
</s>
<s>
Errors	O
in	O
RAM	B-Architecture
introduced	O
by	O
transient	O
faults	O
are	O
often	O
called	O
software	O
errors	O
,	O
the	O
following	O
examples	O
are	O
possible	O
factors	O
that	O
will	O
contribute	O
to	O
transient	O
faults	O
:	O
</s>
