Intel 80286 User Manual

80286 BASE ARCHITECTURE
r--------,
20000 CS
MAIN
PROCEDURE
0 _____ ...
0 _____ ...
2000
o ___ ...
_ __I
L _______ ...J
CURRENTLY
ACCESSIBLE
8000 r-----..,
PROCEDURE
A
___ __I
7253051
DATA (A)
L..- __ --I
8600 r-----.,
0'"- ____ ..1
I
DATA (B)
0
.. ____ --1
Figure 2-1. Segmented Virtual Memory
G3010B
A byte is 8 contiguous bits starting on an addressable byte boundary. The bits are numbered 0 through
7, starting from the right. Bit 7 is the most significant bit:
o
I I i
BYTE
, I
A word is defined as two contiguous bytes starting on an arbitrary byte boundary; a word thus contains
16 bits. The bits are numbered 0 through 15, starting from the right. Bit 15 is the most significant bit.
The byte containing bit 0 of the word
is called the low byte; the byte containing bit 15 is called the
high byte.
15 0
I : : : I : : +W:BY+: : I
LOCATION N + 1
LOCATION N
2-2
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Intel 80286 Specifications

General

Processor Type	Microprocessor
Clock Speed	6 MHz to 25 MHz
Transistor Count	134, 000
Addressable Memory	16 MB
Instruction Set	x86
Architecture	x86
Data Bus Width	16-bit
Address Bus Width	24-bit
Operating Modes	Real mode, Protected mode
Process Technology	1.5 µm
Voltage	5V
Introduced	1982
Package	68-pin PGA