Zilog Z16F2810 User Manual
Page 138
LEA Instruction
UM018809-0611
122
ZNEO
®
CPU Core
User Manual
LEA
Definition
Load Effective address
Syntax
LEA dst, src
Operation
dst
effective address
Description
The LEA instruction is used to load the destination register with a pointer to a memory location.
If an indirect-register source operand is used, the effective address pointed to by the operand is
loaded into the destination register.
The LEA opcodes that take an immediate source operand are assembler synonyms for LD
instructions with the same opcodes. Programs can use LEA with an address operand when the
intention is to load a base address into the destination register. For more information, see the
When the assembler encounters an LD instruction with an immediate source operand, it attempts
to use the shortest possible form, so it may be possible for some LD instructions to disassemble
as LEA.
If the offset required for the PC-based addressing mode exceeds the 14-bit signed range for that
addressing mode, the assembler may silently convert the instruction to use the 32-bit immediate
addressing mode.
Flags
Flags are not affected by this instruction.
Syntax and Opcodes
Instruction, Operands
Word 0
Word 1
Word 2
LEA Rd, soff14(PC)
{002H, Rd}
{1xB, soff14}
LEA Rd, soff14(Rs)
{48H, Rs, Rd}
{1xB, soff14}
LEA Rd, soff6(FP)
{4H, 11B, soff6, Rd}
LEA Rd, imm32
{452H, Rd}
imm[31:16]
imm[15:0]
LEA Rd, simm17
{45H, 000B, simm[16], Rd}
simm[15:0]