<s>
The	O
Zilog	B-Device
eZ80	I-Device
is	O
an	O
8-bit	O
microprocessor	B-Architecture
from	O
Zilog	O
,	O
introduced	O
in	O
2001	O
.	O
eZ80	B-Device
is	O
an	O
updated	O
version	O
of	O
the	O
company	O
's	O
first	O
product	O
,	O
the	O
Z80	B-General_Concept
microprocessor	I-General_Concept
.	O
</s>
<s>
The	O
eZ80	B-Device
(	O
like	O
the	O
Z380	B-Device
)	O
is	O
binary	B-General_Concept
compatible	I-General_Concept
with	O
the	O
Z80	B-General_Concept
and	O
Z180	B-Device
,	O
but	O
almost	O
three	O
times	O
as	O
fast	O
as	O
the	O
original	O
Z80	B-General_Concept
chip	O
at	O
the	O
same	O
clock	O
frequency	O
.	O
</s>
<s>
The	O
eZ80	B-Device
has	O
a	O
three-stage	O
pipeline	O
.	O
</s>
<s>
Available	O
at	O
up	O
to	O
50MHz	O
(	O
2004	O
)	O
,	O
the	O
performance	O
is	O
comparable	O
to	O
a	O
Z80	B-General_Concept
clocked	O
at	O
150MHz	O
if	O
fast	O
memory	O
is	O
used	O
(	O
i.e.	O
</s>
<s>
no	O
wait	O
states	O
for	O
opcode	B-Language
fetches	O
,	O
for	O
data	O
,	O
or	O
for	O
I/O	O
)	O
or	O
even	O
higher	O
in	O
some	O
applications	O
(	O
a	O
16-bit	O
addition	O
is	O
11	O
times	O
as	O
fast	O
as	O
in	O
the	O
original	O
)	O
.	O
</s>
<s>
The	O
eZ80	B-Device
also	O
supports	O
direct	O
continuous	O
addressing	O
of	O
16MB	O
of	O
memory	O
without	O
a	O
memory	B-General_Concept
management	I-General_Concept
unit	I-General_Concept
,	O
by	O
extending	O
most	O
registers	O
(	O
HL	O
,	O
BC	O
,	O
DE	O
,	O
IX	O
,	O
IY	O
,	O
SP	O
,	O
and	O
PC	O
)	O
from	O
16	O
to	O
24	O
bits	O
.	O
</s>
<s>
Z80	B-General_Concept
register	O
pairs	O
are	O
extended	O
to	O
24	O
bits	O
and	O
renamed	O
with	O
U	O
e.g.	O
</s>
<s>
But	O
it	O
can	O
still	O
work	O
in	O
the	O
original	O
Z80-compatible	O
mode	O
.	O
</s>
<s>
The	O
processor	O
has	O
a	O
24-bit	O
ALU	O
arithmetic	B-General_Concept
logic	I-General_Concept
unit	I-General_Concept
and	O
overlapped	O
processing	O
of	O
several	O
instructions	O
(	O
the	O
three-stage	O
pipeline	O
)	O
which	O
are	O
the	O
two	O
primary	O
reasons	O
for	O
its	O
speed	O
.	O
</s>
<s>
Unlike	O
the	O
older	O
Z280	B-Device
and	O
Z380	B-Device
it	O
does	O
not	O
have	O
(	O
or	O
need	O
)	O
a	O
cache	O
memory	O
.	O
</s>
<s>
Instead	O
,	O
it	O
is	O
intended	O
to	O
work	O
with	O
fast	O
SRAM	B-Architecture
directly	O
as	O
main	O
memory	O
(	O
as	O
this	O
had	O
become	O
much	O
cheaper	O
)	O
.	O
</s>
<s>
Nor	O
does	O
it	O
have	O
the	O
multiplexed	O
bus	O
of	O
the	O
Z280	B-Device
,	O
making	O
it	O
as	O
easy	O
to	O
work	O
with	O
(	O
interface	O
to	O
)	O
as	O
the	O
original	O
Z80	B-General_Concept
and	O
Z180	B-Device
,	O
and	O
equally	O
predictable	O
when	O
it	O
comes	O
to	O
exact	O
execution	O
times	O
.	O
</s>
<s>
The	O
chip	O
has	O
a	O
memory	O
interface	O
that	O
is	O
similar	O
to	O
the	O
original	O
Z80	B-General_Concept
,	O
including	O
the	O
bus	O
request/acknowledge	O
pins	O
,	O
and	O
adds	O
four	O
integrated	O
chip	O
selects	O
.	O
</s>
<s>
Versions	O
are	O
available	O
with	O
on-chip	O
flash	O
memory	O
and	O
on-chip	O
zero	O
wait-state	O
SRAM	B-Architecture
(	O
up	O
to	O
256KB	O
flash	O
memory	O
and	O
16KB	O
SRAM	B-Architecture
)	O
but	O
there	O
are	O
also	O
external	O
buses	O
on	O
all	O
models	O
.	O
</s>
<s>
is	O
a	O
family	O
of	O
eZ80	B-Device
single	O
chip	O
computers	O
labeled	O
as	O
"	O
application-specific	O
standard	O
products	O
"	O
(	O
ASSP	O
)	O
that	O
feature	O
up	O
to	O
128KB	O
of	O
flash	O
memory	O
,	O
up	O
to	O
8KB	O
of	O
SRAM	B-Architecture
,	O
and	O
can	O
operate	O
at	O
speeds	O
of	O
up	O
to	O
20MHz	O
.	O
</s>
<s>
Like	O
other	O
eZ80	B-Device
variants	O
,	O
it	O
has	O
an	O
external	O
address	O
and	O
data	O
bus	O
and	O
can	O
thus	O
be	O
used	O
as	O
a	O
general	O
purpose	O
microprocessor	B-Architecture
as	O
well	O
.	O
</s>
<s>
is	O
a	O
family	O
of	O
connectivity	O
ASSPs	O
that	O
feature	O
up	O
to	O
256KB	O
of	O
flash	O
memory	O
,	O
16KB	O
of	O
SRAM	B-Architecture
,	O
can	O
operate	O
at	O
speeds	O
of	O
up	O
to	O
50MHz	O
.	O
</s>
<s>
It	O
adds	O
an	O
integrated	O
10/100BaseT	O
Ethernet	O
MAC	B-Protocol
,	O
TCP/IP	O
stack	O
over	O
the	O
eZ80Acclaim	O
!	O
</s>
<s>
Like	O
other	O
eZ80	B-Device
variants	O
,	O
it	O
has	O
an	O
external	O
address	O
and	O
data	O
bus	O
and	O
can	O
thus	O
be	O
used	O
as	O
a	O
general	O
purpose	O
microprocessor	B-Architecture
as	O
well	O
.	O
</s>
<s>
The	O
latest	O
(	O
mid-2015	O
)	O
graphing	O
calculator	O
in	O
the	O
TI-84	B-Device
line	O
by	O
Texas	O
Instruments	O
,	O
the	O
TI-84	B-Device
Plus	I-Device
CE	O
,	O
uses	O
the	O
eZ80	B-Device
in	O
the	O
24-bit	O
address	O
mode	O
at	O
a	O
clock	O
rate	O
of	O
48MHz	O
.	O
</s>
<s>
In	O
Europe	O
,	O
the	O
TI-84	B-Device
Plus	I-Device
CE-T	O
and	O
TI-83	O
Premium	O
CE	O
are	O
also	O
powered	O
by	O
the	O
eZ80	B-Device
.	O
</s>
