|
| |
Load Effective Address
|
86/88 |
Y |
186 |
Y |
286 |
Y |
386 |
Y |
486 |
Y |
LEA destination, source |
|
Ovfl |
N |
Dir |
N |
Int |
N |
Trap |
N |
Sign |
N |
Zero |
N |
Aux |
N |
Prty |
N |
Carry |
N |
LEA transfers the offset of the source operand (rather than its value)
to the destination operand. The source must be a memory reference, and
the destination must be a 16-bit general register.
Notes: This instruction has an advantage over using the
OFFSET operator with the MOV instruction, in that
the source operand can be subscripted. For example,
this is legal:
LEA BX, TABLE[SI] ;Legal
whereas
MOV BX, OFFSET TABLE[SI] ;Not legal
is illegal, since the OFFSET operator performs its
calculation at assembly time and this address is not
known until run time.
------------------------------------ Timing ----------------------------------
OpCode Instruction 386 286 86
8D/r LEA r16,m 2 3 2+EA
8D/r LEA r32,m 2
------------------------------------ Logic -----------------------------------
destination = addr(source)
See Also LDS LES LFS LGS LSS |