Data Transfer Group

This group of instructions copy data from a location called a source to another location called a destination, without modifying the contents of the source. In technical manuals, the term data transfer is used for this copying function. However, the term transfer is misleading; it creates the impression that the contents of the source are destroyed when, in fact, the contents are retained without any modification. The various types of data transfer (copy) are listed below together with examples of each type:

1. Between Registers. 1. Copy the contents of the register B into register D.
2. Specific data byte to a register or a memory location. 2. Load register B with the data byte 32H.
3. Between a memory location and a register.3. From a memory location 2000H to register B.
4. Between an I/O device and the accumulator. 4.From an input keyboard to the accumulator.

MOV           Move

MVI           Move Immediate

LDA           Load Accumulator Directly from Memory

STA           Store Accumulator Directly in Memory

LHLD          Load H & L Registers Directly from Memory

SHLD          Store H & L Registers Directly in Memory

An 'X' in the name of a data transfer instruction implies that it deals with a register pair (16-bits);

LXI           Load Register Pair with Immediate data

LDAX          Load Accumulator from Address in Register Pair

STAX          Store Accumulator in Address in Register Pair

XCHG          Exchange H & L with D & E

XTHL          Exchange Top of Stack with H & L

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