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Data Transfer Group Instructions (Part-II)

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MVI R, 8-bit data:
  • This instruction moves the 8-bit immediate data to the specified register.
  • This data is given in the instruction itself.
  • R can be any 8-bit general purpose register like A, B, C, D, E, H and L.
  • No flags are affected.
  • It is a two byte instruction.
  • Immediate addressing mode is used in this instruction.
Example:
MVI C, 09H
MVI H, 34H

MVI M, 8-bit data: 
  • This instruction moves the 8-bit immediate data to the memory location pointed by HL register pair.
  • No flags are affected.
  • It is a two byte instruction.
  • Immediate and indirect addressing mode is used in this instruction.
Example:
MVI M, 35H
MVI M, 20H


LXI Rp, 16-bit data:
  • This instruction moves the 16-bit data to the register pair.
  • Only high order register is specified for register pair.
  • Rp can be BC, DE, HL or SP.
  • No flags are affected.
  • It is a three byte instruction.
  • Immediate addressing mode is used in this instruction.
Example:
LXI B, 2030H ; This instruction will load 20H into B register and 30H into C register.
LXI H, 5600H ; This instruction will load 56H into H register and 00H into L register.


NOTE: MVI B, 20H and MVI C, 21H are two instructions used to move 16-bit data 2021H to BC register pair. These two instructions uses 2 bytes each. So total of 4 bytes are used. They can be replaced by one instruction LXI B, 2021H. This instruction uses 3 bytes.

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