Intel 80286 User Manual

OVERVIEW OF NUMERIC PROCESSING
Table 1-14. Packed Decimal Encodings
Magnitude
Class
. Sign
I I I
I
... I
digit digit digit digit
digit
(Largest)
0 0000000 1 0 0 1 1 0 0 1 1 0 0 1 1 o 0 1
· ..
1 0 0 1
· · ·
III
GI
· · ·
·
·
·
.iJj
(Smallest)
0 0000000 o 0 0 0 o 0 0 0 o 0 0 0 o 0 0 0 o 0 0 1
0
· ..
11.
Zero
0 0000000 000 0 o 0 0 0 o 0 0 0 o 0 0 0
...
o 0 0 0
Zero 1 0000000 o 000 o 0 0 0
o 0 0 0
o 0 0 0 ...
o 0 0 0
III
GI
(Smallest) 1
0000000
o 0 0 0 o 0 0 0
o 0 0 0 o 0 0 0 o 0 0 1
.::
· ..
10
/
· ·
·
Dl
GI
· · · z
· · ·
(Largest) 1
0000000 1
o 0 1
1
o 0 1 1 0 0 1
1
001 1 0 0 1
Indefinite' 1
1111111
1 1 1 1 1
1 1 1
U U U U2
U U U U U U U U
1'-1 byte--.I ...... t---------- 9 bytes---------l ... 1
NOTES:
1. The packed decimal indefinite encoding is stored by FBSTP in response to a masked invalid operation
exception. Attempting to load this value via FBLD produces
an undefined result.
2. UUUU means bit values are undefined and may contain any value.
1-30
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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