Data Transfer Group Instructions (Part-II)

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.