<s>
In	O
digital	B-General_Concept
transmission	O
,	O
bit	B-General_Concept
slip	I-General_Concept
is	O
the	O
loss	O
or	O
gain	O
of	O
a	O
bit	O
or	O
bits	O
,	O
caused	O
by	O
clock	O
drift	O
–	O
variations	O
in	O
the	O
respective	O
clock	O
rates	O
of	O
the	O
transmitting	O
and	O
receiving	O
devices	O
.	O
</s>
<s>
One	O
cause	O
of	O
bit	O
slippage	O
is	O
overflow	B-General_Concept
of	O
a	O
receive	O
buffer	O
that	O
occurs	O
when	O
the	O
transmitter	O
's	O
clock	O
rate	O
exceeds	O
that	O
of	O
the	O
receiver	O
.	O
</s>
<s>
This	O
causes	O
one	O
or	O
more	O
bits	O
to	O
be	O
dropped	O
for	O
lack	O
of	O
storage	B-General_Concept
capacity	I-General_Concept
.	O
</s>
<s>
Alternatively	O
,	O
bit	B-General_Concept
slip	I-General_Concept
can	O
be	O
prevented	O
by	O
using	O
a	O
self-clocking	O
signal	O
(	O
such	O
as	O
a	O
signal	O
modulated	O
using	O
OQPSK	O
)	O
or	O
using	O
a	O
line	B-Protocol
coding	I-Protocol
such	O
as	O
Manchester	B-Protocol
encoding	I-Protocol
.	O
</s>
<s>
Another	O
cause	O
is	O
"	O
losing	O
count	O
"	O
,	O
as	O
on	O
a	O
hard	O
drive	O
:	O
if	O
a	O
hard	O
drive	O
encounters	O
a	O
long	O
string	O
of	O
0s	O
,	O
without	O
any	O
1s	O
(	O
or	O
a	O
string	O
of	O
1s	O
without	O
0s	O
)	O
,	O
it	O
may	O
lose	O
track	O
of	O
the	O
frame	O
between	O
fields	O
,	O
and	O
suffer	O
bit	B-General_Concept
slip	I-General_Concept
.	O
</s>
<s>
When	O
a	O
pulse	O
of	O
N	O
consecutive	O
zero	O
bits	O
are	O
sent	O
,	O
clock	O
drift	O
may	O
cause	O
the	O
hardware	O
to	O
apparently	O
detect	O
N-1	O
zero	O
bits	O
or	O
N+1	O
zero	O
bits	O
—	O
both	O
kinds	O
of	O
errors	O
are	O
called	O
bit	B-General_Concept
slip	I-General_Concept
.	O
</s>
<s>
Thus	O
one	O
prevents	O
long	O
strings	O
without	O
change	O
via	O
such	O
devices	O
as	O
run	B-Protocol
length	I-Protocol
limited	I-Protocol
codes	I-Protocol
.	O
</s>
<s>
While	O
a	O
scrambler	O
makes	O
the	O
"	O
losing	O
count	O
"	O
type	O
of	O
bit	B-General_Concept
slip	I-General_Concept
error	O
occur	O
far	O
less	O
often	O
,	O
</s>
<s>
when	O
bit	B-General_Concept
slip	I-General_Concept
errors	O
do	O
occur	O
(	O
perhaps	O
for	O
other	O
reasons	O
)	O
,	O
</s>
<s>
A	O
bit-slip	O
error	O
when	O
using	O
any	O
other	O
block	B-Algorithm
cipher	I-Algorithm
mode	I-Algorithm
of	I-Algorithm
operation	I-Algorithm
generally	O
results	O
in	O
complete	O
corruption	O
of	O
the	O
rest	O
of	O
the	O
message	O
.	O
</s>
