<s>
e	B-Language
is	O
a	O
hardware	B-Language
verification	I-Language
language	I-Language
(	O
HVL	O
)	O
which	O
is	O
tailored	O
to	O
implementing	O
highly	O
flexible	O
and	O
reusable	O
verification	O
testbenches	O
.	O
</s>
<s>
e	B-Language
was	O
first	O
developed	O
in	O
1992	O
in	O
Israel	O
by	O
Yoav	O
Hollander	O
for	O
his	O
Specman	B-Language
software	O
.	O
</s>
<s>
Main	O
features	O
of	O
e	B-Language
are	O
:	O
</s>
<s>
UVM	O
e	B-Language
library	O
and	O
documentation	O
can	O
be	O
downloaded	O
here	O
:	O
</s>
<s>
The	O
e	B-Language
language	O
uses	O
an	O
aspect-oriented	B-Architecture
programming	I-Architecture
(	O
AOP	O
)	O
approach	O
,	O
which	O
is	O
an	O
extension	O
of	O
the	O
object-oriented	B-Language
programming	I-Language
approach	O
to	O
specifically	O
address	O
the	O
needs	O
required	O
in	O
functional	O
verification	O
.	O
</s>
<s>
Executable	O
e	B-Language
code	O
is	O
enclosed	O
within	O
code-segment	O
markers	O
<' and '>	O
:	O
</s>
<s>
e	B-Language
also	O
has	O
two	O
kinds	O
of	O
classes	O
:	O
</s>
<s>
The	O
code	O
segment	O
shows	O
a	O
unit	O
called	O
'	O
environment_u	O
 '	O
being	O
instantiated	O
within	O
the	O
e	B-Language
root	O
'	O
sys	O
 '	O
.	O
</s>
<s>
In	O
e	B-Language
each	O
field	O
is	O
randomized	O
by	O
default	O
.	O
</s>
<s>
e	B-Language
supports	O
assertions	O
with	O
temporal	O
expressions	O
.	O
</s>
<s>
e	B-Language
supports	O
coverage	O
that	O
are	O
grouped	O
according	O
to	O
their	O
sampled	O
event	O
and	O
those	O
groups	O
are	O
internally	O
structured	O
with	O
items	O
.	O
</s>
<s>
Messaging	O
within	O
e	B-Language
can	O
be	O
done	O
with	O
various	O
methods	O
.	O
</s>
<s>
An	O
e	B-Language
testbench	O
is	O
likely	O
to	O
be	O
run	O
with	O
RTL	O
or	O
higher-level	O
models	O
.	O
</s>
<s>
Bearing	O
this	O
in	O
mind	O
,	O
e	B-Language
is	O
capable	O
of	O
interfacing	O
with	O
VHDL	B-Language
,	O
Verilog	B-Language
,	O
C	B-Language
,	O
C++	B-Language
and	O
SystemVerilog	B-Language
.	O
</s>
<s>
This	O
necessity	O
calls	O
for	O
a	O
language	O
that	O
is	O
capable	O
of	O
encapsulating	O
data	O
and	O
models	O
,	O
which	O
is	O
readily	O
available	O
in	O
object-oriented	B-Language
languages	I-Language
.	O
</s>
<s>
To	O
address	O
this	O
need	O
has	O
been	O
designed	O
to	O
be	O
e	B-Language
an	O
object-oriented	B-Language
language	I-Language
and	O
on	O
top	O
of	O
that	O
has	O
been	O
augmented	O
with	O
aspect-oriented	B-Architecture
mechanisms	O
that	O
facilitate	O
not	O
only	O
writing	O
highly	O
flexible	O
and	O
reusable	O
testbenches	O
,	O
but	O
also	O
helps	O
verification	O
engineers	O
by	O
enabling	O
to	O
patch	O
discovered	O
RTL	O
bugs	O
without	O
having	O
to	O
rewrite	O
or	O
touch	O
any	O
of	O
the	O
already	O
existing	O
code	O
base	O
.	O
</s>
<s>
Aspect-oriented	B-Architecture
programming	I-Architecture
in	O
e	B-Language
allows	O
verification	O
engineers	O
to	O
structure	O
their	O
testbench	O
in	O
aspects	O
.	O
</s>
<s>
The	O
following	O
sections	O
illustrate	O
basic	O
aspect-oriented	B-Architecture
mechanisms	O
in	O
e	B-Language
.	O
</s>
<s>
Subtyping	O
is	O
the	O
prime	O
example	O
of	O
what	O
object-oriented	B-Language
languages	I-Language
without	O
aspect-oriented	B-Architecture
features	O
can	O
not	O
accomplish	O
.	O
</s>
<s>
The	O
original	O
unit	O
definition	O
is	O
given	O
in	O
file1.e	O
.	O
</s>
<s>
The	O
aspect-oriented	B-Architecture
mechanism	O
used	O
in	O
this	O
example	O
shows	O
how	O
to	O
execute	O
code	O
before	O
and	O
after	O
an	O
already	O
implemented	O
method	O
.	O
</s>
