Intel 80286, 80287 manual LSL-LoadSegment Limit, 14,mem=16 Load rw = Segment Limit, selector ew

THE 80286 INSTRUCTION SET

LSL-LoadSegment Limit

OpcodeInstruction ClocksDescription

OF 03 /r LSL rw,ew 14,mem=16 Load: rw = Segment Limit, selector ew

FLAGS MODIFIED

Zero

FLAGS UNDEFINED

None

OPERATION

If the descriptor denoted by the selector in the second (memory or register) operand is visible at the CPL, a word that consists of the limit field of the descriptor is loaded into the left operand, which must be a register. The value is the limit field for that segment. The zero flag is set if the loading was performed (that is, if the selector is non-null, the selector index is within the descriptor table limits, the descriptor is a non-conforming segment descriptor with DPL ;::: CPL, and the descriptor DPL ;::: selector RPL); the zero flag is cleared otherwise.

The LSL instruction returns only the limit field of segments,task state segments, and local descriptor

tables. The interpretation of the limit value depends on the type of segment. .

The selector.operand's value cannot result in a protection exce,l?tion..

PROTECTED MODE EXCEPTIONS

#GP(O) for an illegal memory operand effective address in the CS, DS, or ES segments; #SS(O) for an illegal address in the SS segment.

REAL ADDRESS MODE EXCEPTIONS

Interrupt 6; LSL is not recognized in Real Address mode.

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