User's Manual

THE 80286 INSTRUCTION SET
OUT -Output to Port
Opcode
Instruction
E6 db
OUT db,AL
E7
db
OUT db,AX
EE
OUT OX,AL
EF
OUT OX,AX
FLAGS MODIFIED
None
FLAGS UNDEFINED
None
OPERATION
Clocks
3
3
3
3
Description
Output byte AL to
immediate port number db.
Output word AX to immediate port number db
Output byte AL to port number OX
Output word AX to port number OX
OUT transfers a data byte or data word from the register CAL or AX) given.as the second operand to
the output port numbered by the first operand. You can output to any port from{)-65535 by placing
the port number in the DX register then using an
OUT instruction with DX as the first operand. If the
instruction contains an 8-bit port ID,
that value is zero-extended to 16 bits.
Intel reserves
I/0 port addresses OOF8H through OOFFH; these addresses should not be used.
PROTECTED MODE EXCEPTIONS
#GP(O) if the current privilege level is bigger (has less privilege) than IOPL, which is the privilege
level found in the flags register.
REAL ADDRESS MODE EXCEPTIONS
None
8-81