Intel 80287, 80286 manual POPF-Pop from Stack into the Flags Register, Popf

THE 80286 INSTRUCTION SET

POPF-Pop from Stack into the Flags Register

OpcodeInstruction ClocksDescription

9D POPF 5 Pop top of stack into flags register

FLAGS MODIFIED

Entire flags register is popped from stack

FLAGS UNDEFINED

None

OPERATION

The top of the 80286 stack, pointed to by SS:SP, is copied into the 80286 flags register. The stack pointer SP is incremented by 2to point to the new top of stack. The flags, from the top bit (bit 15) to the bottom (bit 0), are as follows: undefined, nested task, I/O privilege level (2 bits), overflow, direc- tion, interrupts enabled, trap, sign, zero, undefined, auxiliary carry, undefined, parity, undefined, and carry.

The I/O privilege level will be altered only when executing at privilege level O. The interrupt enable flag will be altered only whim executing at a level at least as privileged as the I/O privilege level. If you execute a POPF instruction with insufficient privilege, there will be no exception nor will the privileged bits be changed.

PROTECTED MODE EXCEPTIONS

#SS(O).if the top of stack is not within the stack segment.

REAL ADDRESS MODE EXCEPTIONS

Interrupt 13 for a word operand at OFFFFH.

In real mode the NT and 10PL bits will not be modified.

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