Intel 253666-024US User Manual
Page 515
Vol. 2A 3-469
INSTRUCTION SET REFERENCE, A-M
INS/INSB/INSW/INSD—Input from Port to String
IF (Byte transfer)
THEN IF DF
=
0
THEN (E)DI
← (E)DI + 1;
ELSE (E)DI ← (E)DI – 1; FI;
ELSE IF (Word transfer)
THEN IF DF
=
0
THEN (E)DI
← (E)DI + 2;
ELSE (E)DI ← (E)DI – 2; FI;
ELSE (* Doubleword transfer *)
THEN IF DF
=
0
THEN (E)DI
← (E)DI + 4;
ELSE (E)DI ← (E)DI – 4; FI;
FI;
FI;
FI64-bit Mode:
IF (Byte transfer)
THEN IF DF
=
0
THEN (E|R)DI
← (E|R)DI + 1;
ELSE (E|R)DI ← (E|R)DI – 1; FI;
ELSE IF (Word transfer)
THEN IF DF
=
0
THEN (E)DI
← (E)DI + 2;
ELSE (E)DI ← (E)DI – 2; FI;
ELSE (* Doubleword transfer *)
THEN IF DF
=
0
THEN (E|R)DI
← (E|R)DI + 4;
ELSE (E|R)DI ← (E|R)DI – 4; FI;
FI;
FI;
Flags Affected
None.
Protected Mode Exceptions
#GP(0)
If the CPL is greater than (has less privilege) the I/O privilege
level (IOPL) and any of the corresponding I/O permission bits in
TSS for the I/O port being accessed is 1.
If the destination is located in a non-writable segment.
If an illegal memory operand effective address in the ES
segments is given.
#PF(fault-code)
If a page fault occurs.