Intel 80286 User Manual

MACHINE INSTRUCTION ENCODING AND DECODING
Table A-2. Machine Instruction Decoding Guide (Cont'd.)
1st Byte
2nd Byte Bytes 3, 4
ASM286 Instruction
Hex
Binary
Format
DF 1101 1111 1100 1REG
*(7)
OF 1101 1111 1101 OREG
*(8)
OF 1101 1111 1101
1REG *(9)
OF 1101 1111 1110 000
FSTSWAX
OF 1101 1111
1111
XXX reserved
NOTE:
* The marked encodings are not generated by the language translators. If, however, the 80287 encounters
one of these encodings
in the instruction stream, it will execute it as follows:
(1) FSTP STeil
(2) FCOM STeil
(3) FCOMP STeil
(4) FXCH STeil
(5) FCOMP STeil
(6) FFREE STeil and pop stack
(7) FXCH STeil
(8) FSTP STeil
(9) FSTP STeil
A-5
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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