<s>
MikroSim	B-Application
is	O
an	O
educational	B-Application
software	I-Application
computer	O
program	O
for	O
hardware-non-specific	O
explanation	O
of	O
the	O
general	O
functioning	O
and	O
behaviour	O
of	O
a	O
virtual	O
processor	B-General_Concept
,	O
running	O
on	O
the	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
Devices	O
like	O
miniaturized	O
calculators	B-Application
,	O
microcontroller	B-Architecture
,	O
microprocessors	B-General_Concept
,	O
and	O
computer	O
can	O
be	O
explained	O
on	O
custom-developed	O
instruction	O
code	O
on	O
a	O
register	O
transfer	O
level	O
controlled	O
by	O
sequences	O
of	O
micro	O
instructions	O
(	O
microcode	B-Device
)	O
.	O
</s>
<s>
Based	O
on	O
this	O
it	O
is	O
possible	O
to	O
develop	O
an	O
instruction	B-General_Concept
set	I-General_Concept
to	O
control	O
a	O
virtual	O
application	O
board	O
at	O
higher	O
level	O
of	O
abstraction	O
.	O
</s>
<s>
Initially	O
MikroSim	B-Application
was	O
developed	O
to	O
be	O
a	O
processor	B-General_Concept
simulation	O
software	O
to	O
be	O
widely	O
available	O
in	O
educational	O
areas	O
.	O
</s>
<s>
Since	O
MikroSim	B-Application
operability	O
starts	O
on	O
the	O
basis	O
of	O
microcode	B-Device
development	O
,	O
defined	O
as	O
a	O
sequence	O
of	O
micro	O
instructions	O
(	O
microcoding	B-Device
)	O
for	O
a	O
virtual	O
control	B-General_Concept
unit	I-General_Concept
,	O
the	O
software	O
's	O
intention	O
is	O
on	O
first	O
approach	O
a	O
microcode	B-Device
simulator	O
with	O
various	O
levels	O
of	O
abstractions	O
including	O
the	O
ability	O
of	O
CPU	O
simulators	O
and	O
instruction	B-General_Concept
set	I-General_Concept
emulators	O
.	O
</s>
<s>
In	O
the	O
current	O
software	O
revision	O
it	O
is	O
feasible	O
for	O
a	O
microcode	B-Device
controlled	O
virtual	O
application	O
to	O
operate	O
on	O
own	O
coded	O
instruction	B-General_Concept
sets	I-General_Concept
.	O
</s>
<s>
With	O
MikroSim	B-Application
typical	O
and	O
well-known	O
concepts	O
in	O
the	O
area	O
of	O
computer	O
engineering	O
like	O
computer	B-General_Concept
architecture	I-General_Concept
and	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
are	O
non-specifically	O
treated	O
,	O
which	O
have	O
been	O
established	O
since	O
the	O
early	O
days	O
of	O
the	O
information	O
era	O
and	O
being	O
still	O
valid	O
.	O
</s>
<s>
The	O
detailed	O
documentation	O
and	O
the	O
bilingual	O
application	O
's	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
in	O
German	O
and	O
English	O
,	O
as	O
well	O
as	O
the	O
software	O
's	O
upward	O
compatibility	O
given	O
to	O
some	O
extent	O
by	O
Microsoft	O
's	O
operating	B-General_Concept
system	I-General_Concept
Windows	O
,	O
are	O
reasons	O
for	O
being	O
a	O
well-established	O
,	O
valuable	O
e-learning	O
tool	O
in	O
the	O
field	O
of	O
computer	O
engineering	O
since	O
1992	O
for	O
educational	O
use	O
.	O
</s>
<s>
The	O
software	O
is	O
based	O
on	O
a	O
version	O
written	O
under	O
Turbo	B-Application
Pascal	I-Application
compiled	O
for	O
MS-DOS	B-Application
operating	B-General_Concept
systems	I-General_Concept
which	O
has	O
been	O
used	O
for	O
educational	O
purposes	O
in	O
computer	O
engineering	O
and	O
computer	B-General_Concept
science	I-General_Concept
at	O
the	O
Philipps-University	O
Marburg	O
(	O
Germany	O
)	O
until	O
1992	O
.	O
</s>
<s>
The	O
concept	O
was	O
picked	O
up	O
by	O
Martin	O
Perner	O
during	O
his	O
study	O
of	O
physics	O
(	O
1990	O
–	O
95	O
)	O
in	O
summer	O
1992	O
,	O
revised	O
,	O
and	O
converted	O
into	O
a	O
windows	O
application	O
compiled	O
with	O
Microsoft	O
Visual	B-Language
Basic	I-Language
and	O
running	O
on	O
Windows	B-Application
3.1x	I-Application
.	O
</s>
<s>
In	O
doing	O
so	O
,	O
at	O
this	O
time	O
a	O
simulator	O
with	O
huge	O
conceptual	O
improvements	O
arose	O
by	O
exploiting	O
the	O
novel	O
functionality	O
and	O
utilisation	O
of	O
MS	O
Windows’	O
GUI	B-Application
for	O
supporting	O
the	O
composition	O
of	O
microcode	B-Device
and	O
the	O
traceability	O
of	O
its	O
instructional	O
influence	O
.	O
</s>
<s>
The	O
Simulator	O
has	O
been	O
awarded	O
with	O
the	O
‘’	O
European	O
Academic	O
Software	O
Award	O
1994’’	O
in	O
the	O
computer	B-General_Concept
science	I-General_Concept
category	O
in	O
Heidelberg	O
(	O
Germany	O
)	O
in	O
November	O
1994	O
.	O
</s>
<s>
Between	O
1995	O
and	O
2000	O
the	O
simulator	O
was	O
published	O
as	O
‘’	O
Mikrocodesimulator	O
MikroSim	B-Application
1.2	O
’’	O
without	O
any	O
significant	O
improvements	O
.	O
</s>
<s>
In	O
its	O
penultimate	O
revision	O
,	O
the	O
simulator	O
has	O
been	O
published	O
under	O
‘’	O
Mikrocodesimulator	O
MikroSim2000’’	O
,	O
optimized	O
for	O
MS	B-Application
Windows	I-Application
95	I-Application
’s	O
32-bit	O
operation	O
.	O
</s>
<s>
So	O
it	O
has	O
received	O
wide-ranging	O
improvements	O
and	O
extensions	O
without	O
touching	O
the	O
successful	O
conceptual	O
aspects	O
of	O
the	O
microcode	B-Device
simulation	O
abilities	O
in	O
the	O
core	O
.	O
</s>
<s>
For	O
this	O
purpose	O
,	O
advantage	O
is	O
taken	O
of	O
today	O
’s	O
computing	O
system	O
’s	O
performance	O
determined	O
by	O
operating	B-General_Concept
system	I-General_Concept
and	O
underlying	O
computational	O
power	O
to	O
extend	O
MikroSim	B-Application
’s	O
simulation	O
possibilities	O
up	O
to	O
the	O
stage	O
of	O
a	O
virtual	O
application	O
board	O
.	O
</s>
<s>
MikroSim	B-Application
is	O
compiled	O
and	O
optimized	O
for	O
sake	O
of	O
unrestricted	O
compatibility	O
and	O
for	O
widest	O
distribution	O
possible	O
for	O
MS	B-Application
Windows	I-Application
XP	I-Application
as	O
a	O
32-bit	O
version	O
.	O
</s>
<s>
The	O
program	O
runs	O
on	O
all	O
32	O
-	O
and	O
64-bit	O
operating	B-General_Concept
systems	I-General_Concept
of	O
MS	B-Application
Windows	I-Application
Vista	I-Application
and	O
MS	B-Device
Windows	I-Device
7	I-Device
.	O
</s>
<s>
Thereby	O
,	O
no	O
special	O
XP	B-Application
compatibility	O
mode	O
is	O
needed	O
.	O
</s>
<s>
Since	O
January	O
2010	O
,	O
the	O
simulator	O
is	O
distributed	O
as	O
‘’	O
Mikrocodesimulator	O
MikroSim	B-Application
2010’’	O
by	O
0/1	O
-SimWare	O
.	O
</s>
<s>
In	O
exploration	O
mode	O
,	O
the	O
operating	O
principle	O
and	O
control	O
of	O
newly	O
added	O
components	O
influenced	O
by	O
one	O
microcode	B-Device
instruction	O
within	O
a	O
cycle	O
can	O
be	O
evaluated	O
.	O
</s>
<s>
The	O
width	O
of	O
MikroSim	B-Application
’s	O
micro	O
instructions	O
is	O
49	O
bits	O
.	O
</s>
<s>
In	O
simulation	O
mode	O
,	O
seamlessly	O
executed	O
micro	O
instructions	O
control	O
the	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
of	O
the	O
simulator	O
in	O
subsequent	O
cycles	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
intrinsic	O
ability	O
of	O
one	O
micro	O
instruction	O
is	O
utilized	O
to	O
address	O
the	O
next	O
micro	O
instruction	O
in	O
the	O
control	B-General_Concept
store	I-General_Concept
.	O
</s>
<s>
The	O
control	B-General_Concept
store	I-General_Concept
holding	O
the	O
micro	O
instruction	B-General_Concept
set	I-General_Concept
(	O
commonly	O
referred	O
as	O
"	O
microcode	B-Device
"	O
)	O
comprises	O
1024	O
micro	O
instructions	O
words	O
each	O
49-bit	O
wide	O
.	O
</s>
<s>
Using	O
structuring	O
opportunities	O
of	O
the	O
control	B-General_Concept
store	I-General_Concept
for	O
addressable	O
scheduling	O
of	O
the	O
microcode	B-Device
and	O
the	O
implementation	O
of	O
a	O
cyclically	O
operating	O
machine	B-Language
code	I-Language
interpreter	B-Application
,	O
that	O
is	O
programmed	O
in	O
microcode	B-Device
as	O
well	O
allows	O
the	O
implementation	O
of	O
individual	O
micro-operation	B-General_Concept
sequences	O
,	O
known	O
as	O
machine	B-Language
instructions	I-Language
.	O
</s>
<s>
The	O
microcode	B-Device
can	O
be	O
regarded	O
as	O
firmware	B-Application
for	O
MikroSim	B-Application
,	O
that	O
can	O
be	O
modified	O
,	O
and	O
stored	O
in	O
and	O
reloaded	O
from	O
a	O
microcode-ROM-file	O
.	O
</s>
<s>
Via	O
the	O
input-output	O
controller	O
device	O
,	O
communication	O
with	O
virtual	O
input	O
and	O
output	O
devices	O
is	O
supported	O
by	O
Direct	B-General_Concept
Memory	I-General_Concept
Access	I-General_Concept
mode	O
(	O
DMA	O
)	O
,	O
Inter-Integrated	O
Circuit	O
Connection	O
(	O
I2C	O
)	O
,	O
and	O
Interrupt	B-Application
request	O
functionality	O
(	O
IRQ	O
)	O
.	O
</s>
<s>
The	O
microcode	B-Device
simulator	O
uses	O
eight	O
freely	O
usable	O
register	O
each	O
32-bit	O
wide	O
connected	O
with	O
a	O
32-bit	O
arithmetic	B-General_Concept
logic	I-General_Concept
unit	I-General_Concept
(	O
ALU	O
)	O
.	O
</s>
<s>
The	O
register	O
content	O
can	O
be	O
regarded	O
as	O
signed	O
or	O
unsigned	O
integer	O
values	O
,	O
or	O
as	O
32-bit	O
floating	B-Algorithm
point	I-Algorithm
numbers	I-Algorithm
.	O
</s>
<s>
The	O
32-bit	O
ALU	O
is	O
the	O
key	O
unit	O
of	O
the	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
.	O
</s>
<s>
It	O
supports	O
128	O
different	O
basic	O
arithmetic	O
operations	O
for	O
integer	O
operation	O
,	O
interrupt	B-Application
control	O
,	O
and	O
for	O
floating	B-Algorithm
point	I-Algorithm
arithmetic	I-Algorithm
.	O
</s>
<s>
The	O
didactical	O
approach	O
to	O
floating	B-Algorithm
point	I-Algorithm
calculations	O
,	O
which	O
has	O
been	O
introduced	O
in	O
a	O
comparable	O
manner	O
already	O
in	O
the	O
early	O
1940s	O
by	O
Konrad	O
Zuse	O
,	O
is	O
introduced	O
by	O
using	O
elemental	O
sublevel	O
operations	O
for	O
exponent	O
and	O
mantissa	O
involved	O
in	O
the	O
key	O
operations	O
of	O
addition/subtraction	O
and	O
multiplication/division	O
.	O
</s>
<s>
A	O
set	O
of	O
powerful	O
32-bit	O
floating	B-Algorithm
point	I-Algorithm
arithmetic	I-Algorithm
commands	O
in	O
mantissa	O
and	O
exponent	O
for	O
the	O
basic	O
operations	O
and	O
elementary	O
analytical	O
functions	O
are	O
provided	O
,	O
as	O
they	O
are	O
realized	O
in	O
today	O
's	O
mathematical	O
coprocessors	O
.	O
</s>
<s>
Here	O
,	O
in	O
the	O
simulation	O
with	O
MikroSim	B-Application
it	O
is	O
ideally	O
assumed	O
that	O
the	O
execution	O
of	O
each	O
supported	O
ALU	O
arithmetic	O
operation	O
requires	O
only	O
a	O
distinct	O
computing	O
duration	O
independent	O
of	O
circuit	O
complexity	O
realistically	O
needed	O
in	O
practice	O
.	O
</s>
<s>
The	O
LIE	O
cycle	O
regarded	O
as	O
an	O
interpreter	B-Application
written	O
in	O
microcode	B-Device
has	O
the	O
function	O
to	O
load	O
machine	B-Language
instructions	I-Language
coded	O
as	O
byte	O
value	O
from	O
the	O
external	O
RAM	O
and	O
to	O
let	O
branch	O
the	O
micro	O
instruction	O
sequence	O
to	O
the	O
referenced	O
microcode	B-Device
subroutine	O
for	O
execution	O
given	O
by	O
the	O
opcode	O
and	O
returning	O
to	O
the	O
LIE	O
back	O
to	O
retrieve	O
the	O
next	O
machine	B-Language
instruction	I-Language
.	O
</s>
<s>
One	O
execution	O
level	O
higher	O
,	O
a	O
sequence	O
of	O
several	O
machine	B-Language
instructions	I-Language
are	O
executable	O
until	O
a	O
user-defined	O
break	O
point	O
is	O
reached	O
,	O
which	O
is	O
placed	O
in	O
the	O
machine	B-Language
code	I-Language
sequence	O
.	O
</s>
<s>
So	O
it	O
is	O
possible	O
to	O
benchmark	O
execution	O
performance	O
on	O
machine	O
and	O
microcode	B-Device
level	O
.	O
</s>
<s>
In	O
the	O
top	O
most	O
simulation	O
level	O
the	O
microcode	B-Device
simulator	O
continuously	O
executes	O
micro	O
instructions	O
without	O
interrupt	B-Application
.	O
</s>
<s>
In	O
this	O
level	O
,	O
machine	B-Language
instruction	I-Language
by	O
machine	B-Language
instruction	I-Language
is	O
loaded	O
.	O
</s>
<s>
The	O
performance	O
index	O
monitor	O
provided	O
with	O
the	O
simulator	O
enables	O
the	O
user	O
to	O
benchmark	O
the	O
processing	O
performance	O
of	O
MikroSim	B-Application
and	O
setting	O
it	O
into	O
relation	O
with	O
computing	O
power	O
of	O
the	O
simulator	O
's	O
hardware	O
,	O
measurable	O
in	O
floating-point	B-Algorithm
operations	O
per	O
second	O
(	O
FLOPS	O
)	O
and	O
instructions	O
per	O
second	O
(	O
IPS	O
)	O
.	O
</s>
<s>
With	O
the	O
so-called	O
’’	O
Basic	O
Assembler	B-Language
Tool	O
for	O
MikroSim’’	O
MikroBAT	O
,	O
simple	O
programs	O
can	O
be	O
developed	O
in	O
assembler	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Here	O
,	O
all	O
supported	O
mnemonics	O
of	O
the	O
assembler	B-Language
programming	I-Language
language	I-Language
are	O
determined	O
by	O
the	O
user	O
's	O
self-created	O
machine	O
's	O
instruction	B-General_Concept
set	I-General_Concept
on	O
micro	O
instruction	O
level	O
.	O
</s>
<s>
The	O
add-on	O
tool	O
is	O
able	O
to	O
translate	O
the	O
assembly	B-Language
language	I-Language
program	O
into	O
machine	B-Language
code	I-Language
and	O
data	O
and	O
transferring	O
the	O
binary	O
code	O
into	O
the	O
external	O
RAM	O
for	O
subsequent	O
simulations	O
.	O
</s>
<s>
Together	O
with	O
MikroBAT	O
the	O
microcode	B-Device
simulator	O
MikroSim	B-Application
supports	O
the	O
didactical	O
introduction	O
of	O
teaching	O
aspects	O
in	O
technical	O
computer	B-General_Concept
science	I-General_Concept
from	O
a	O
switch-controlled	O
calculating	O
machine	O
to	O
an	O
assembler	B-Language
programmable	O
application	O
.	O
</s>
