INTO Interrupt on Overflow Flags: O D I T S Z A P C
0 0
INTO
Logic: if (OF = 1)
PUSHF ; Push flags onto stack
TF 0 ; Clear Trap Flag
IF 0 ; Disable Interrupts
CALL FAR (10h) ; The INTO vector is at 0000:0010h
INTO activates interrupt type 4 if the Overflow Flag is set; otherwise
it does nothing. This interrupt operates identically to an "INT 4" if
the overflow flag is set, in which case INTO pushes the flags
register, clears the Trap and Interrupt-enable Flags, pushes CS and
IP, then transfers control to the interrupt-num 4 handler, which is
pointed to by the vector at location 10h. If the interrupt handler
returns using an IRET instruction, the original flags are restored.
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Operands Clocks Transfers Bytes Example
byte(word)
no operands 53 or 4 5 1 INTO
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Notes: The flags are stored in the same format as that used
by the PUSHF instruction.
INTO can be used after an operation that may cause
overflow, to call a recovery procedure.
Seealso:
This page last updated on Fri Nov 30 10:49:50 MSK 2001
Copyright © 1992-2001, Vitaly Filatov, Moscow, Russia
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