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Data Transfer Group Instructions (Part-III)

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LDA addr: 
  • This instruction copies the contents of the memory location to the accumulator.
  • The address of the memory location is given in the instruction itself.
  • No flags are modified.
  • It is a three byte instruction.
  • Direct addressing mode is used.
Example:
If (5600H) = 20H
LDA 5600H ; This instruction loads the contents of location 5600H i.e. 20H into A.

If (1000H) = 1FH
LDA 1000H ; This instruction loads the contents of location 1000H i.e. 1FH into A.

STA addr: 
  • This instruction stores the contents of the accumulator in the memory location.
  • The address of the memory location is given in the instruction itself.
  • No flags are modified.
  • It is a three byte instruction.
  • Direct addressing mode is used.
Example:
If A = 34H
STA 5800H ; This instruction copies the contents of A i.e. 34H to location 5800H.

If A = 32H
STA 1500H ; This instruction copies the contents of A i.e. 32H to location 1500H.

LHLD addr: 
  • This instruction copies the contents of the memory location to the H and L registers.
  • The address of the memory location is given in the instruction itself.
  • The contents of the memory location specified is transferred to L register and the contents of the next memory location is transferred to H register.
  • No flags are modified.
  • It is a three byte instruction.
  • Direct addressing mode is used.
Example:
LHLD 2200H ; This instruction will copy the contents of location 2200H into L register and the contents of location 2201H into H register.

LHLD 5820H ; This instruction will copy the contents of location 5820H into L register and the contents of location 5821H into H register.

SHLD addr:
  • This instruction copies the contents of registers H and L in the memory location.
  • The address of the memory location is given in the instruction itself.
  • The contents of L register is stored in the memory location specified and the contents of H register is stored in the next memory location.
  • No flags are modified.
  • It is a three byte instruction.
  • Direct addressing mode is used.
Example:
SHLD 2000H ; This instruction will copy the contents of L register to location 2000H and the contents of H register to location 2001H.

SHLD 4320H ; This instruction will copy the contents of L register to location 4320H and the contents of H register to location 4321H.
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