# Memory Testing

Topics: Psychology, Model Pages: 11 (322 words) Published: March 29, 2013
Memory
TESTING

Vannapha Phommathansy Yi Lan Suhas Shanker Prodduturi Prashant Tripathi Balaji Panda

Agenda

1.  Brief
overview
of
Memory
2.  Fault
type
,
Fault
modeling

3.  5.  6.  7.

Discuss
FuncEonal
fault
and
Reduce
FF

Coupling
fault
decoder
fault
March
test
Algorithm

8.
Conclusion

9.
Q&A

Overview
of
Memory

ü Memory
is
the
most
dense
physical
structure

ü Considering
the
increase
density,
memory
arrays
are
more
sensiEve
to
defects

DRAM
FLASH

Semiconductor
memory

SRAM

ROM

CDRAM

Test
Eme
in
Sec
VS
size
n
bit

Fault
Types

1.  Permanent:
can’t
be
model
,
system
is
broken
and
fault
exist
indeﬁnitely
2.  Transient:
non
permanent
cause
by
environmental
condiEon
can
be
ﬁx
3.  Intermi\ent:
caused
by
non
environmental
condiEon,
occur
randomly.

Fault
Modeling

Ø Behavior
Ø FuncEonal

Ø Logic
Gate
Ø Electrical

Ø Geometrical

²
Simpliﬁed
²  Reduce
funcEonal
test

²  Subset
funcEonal
test

FuncEonal
Memory
Model

Reduce
funcEonal
fault

SAF
–
Stuck
at
fault
TF
–
TransiEon
fault
CF
-­‐
coupling
Fault
Decoder
Fault

1.  CF
Inversion
2.  CF
Idempotent
3.  Bridging
Fault
4.  Dynamic
fault
5.  State
Coupling

6.  NPSF
-­‐
Neighbor
pa\ern
sensiEve
fault

Reduce
funcEonal
fault
modeling

•  SAF
:

the
logic
value
of
a
cell
or
line
is
always
0
(SA0)
or
always
1
(SA1).

•  TF:
is
a
special
case
of
the
SAF,
in
which
a
cell
fails
to
make
a
(up)
transiEon
or
a
(down)
transiEon
when
it
is
wri\en.
•  CF:
a
transiEon
in
memory
bit
j
causes
an
unwanted
change
in
memory
bit
i.

•  NPSF:
the
content
of
cell
j
changes
and
it
is
inﬂuenced
by
the
contents
of
all
other
memory
cells
The
fault
that
aﬀect
the
decoder
funcEon

Stuck
at
fault
Nota,on:

The
way
to
detect
and
locate:
From
each
cell,
a
0
and
a
1
must
be

Transi,on
Fault
Nota,on: