<s>
Electronic	B-Language
circuit	I-Language
simulation	I-Language
uses	O
mathematical	O
models	O
to	O
replicate	O
the	O
behavior	O
of	O
an	O
actual	O
electronic	O
device	O
or	O
circuit	O
.	O
</s>
<s>
Electronics	B-Language
simulation	I-Language
software	O
engages	O
its	O
users	O
by	O
integrating	O
them	O
into	O
the	O
learning	O
experience	O
.	O
</s>
<s>
In	O
particular	O
,	O
for	O
integrated	O
circuits	O
,	O
the	O
tooling	O
(	O
photomasks	B-Algorithm
)	O
is	O
expensive	O
,	O
breadboards	O
are	O
impractical	O
,	O
and	O
probing	O
the	O
behavior	O
of	O
internal	O
signals	O
is	O
extremely	O
difficult	O
.	O
</s>
<s>
The	O
most	O
well	O
known	O
analog	O
simulator	O
is	O
SPICE	B-Protocol
.	O
</s>
<s>
Probably	O
the	O
best	O
known	O
digital	O
simulators	O
are	O
those	O
based	O
on	O
Verilog	B-Language
and	O
VHDL	B-Language
.	O
</s>
<s>
These	O
models	O
typically	O
include	O
IC	O
specific	O
transistor	O
models	O
such	O
as	O
BSIM	O
,	O
generic	O
components	O
such	O
as	O
resistors	O
,	O
capacitors	O
,	O
inductors	O
and	O
transformers	B-Algorithm
,	O
user	O
defined	O
models	O
(	O
such	O
as	O
controlled	O
current	O
and	O
voltage	O
sources	O
,	O
or	O
models	O
in	O
Verilog-A	B-Language
or	O
VHDL-AMS	B-Language
)	O
.	O
</s>
<s>
While	O
there	O
are	O
strictly	O
analog	O
electronics	B-Language
circuit	I-Language
simulators	I-Language
,	O
popular	O
simulators	O
often	O
include	O
both	O
analog	O
and	O
event-driven	O
digital	O
simulation	O
capabilities	O
,	O
and	O
are	O
known	O
as	O
mixed-mode	O
simulators	O
.	O
</s>
<s>
Because	O
the	O
event	O
driven	O
algorithm	O
is	O
faster	O
than	O
the	O
standard	O
SPICE	B-Protocol
matrix	O
solution	O
,	O
simulation	O
time	O
is	O
greatly	O
reduced	O
for	O
circuits	O
that	O
use	O
event	O
driven	O
models	O
in	O
place	O
of	O
analog	O
models	O
.	O
</s>
<s>
These	O
two	O
modeling	O
techniques	O
use	O
SPICE	B-Protocol
to	O
solve	O
a	O
problem	O
while	O
the	O
third	O
method	O
,	O
digital	O
primitives	O
,	O
use	O
mixed	O
mode	O
capability	O
.	O
</s>
<s>
Process	B-Algorithm
variations	I-Algorithm
occur	O
when	O
the	O
design	O
is	O
fabricated	B-Architecture
and	O
circuit	B-Language
simulators	I-Language
often	O
do	O
not	O
take	O
these	O
variations	O
into	O
account	O
.	O
</s>
