Question

Problem 1.7: Find the addressing modes of the below instructions Memory addressing mode Instruction MOV A, RO; MOV A, @RO; MOV A, #30H; MOV A, 30H; MOVA, @A+DPTR MOV C, A.O; MOV C, 31H; AJMP 3001H; MOV A, 70H;

Answer 1

PLEASE REFER BELOW EXPLANATION

1) MOV A,R0
Answer : Register addressing mode
Explanation :
MOV source,Destination
In the register addressing mode the source or destination data should be present in a register (R0 to R7).

2) MOV A,@R0
Answer : Register indirect addressing Mode
Explanation :
In this mode, the source or destination address is given in the register. By using register indirect addressing mode,
the internal or external addresses can be accessed. The R0 and R1 are used for 8-bit addresses

3) MOV A, #30H
Answer : Immediate addressing mode
Explanation :
In this Immediate Addressing Mode, the data is provided in the instruction itself. The data is provided immediately after the opcode.

4) MOV A, 30H
Answer : Direct Addressing Mode
Explanation :
In the Direct Addressing Mode, the source or destination address is specified by using 8-bit data in the instruction.
Only the internal data memory can be used in this mode.

5) MOV A,@A+DPTR
Answer : Indexed addressing mode
Explanation:
In the indexed addressing mode, the source memory can only be accessed from program memory only. The destination operand is always the register A.

6) MOV C, A.0
Answer : Register addressing mode
Explanation :
MOV source,Destination
In the register addressing mode the source or destination data should be present in a register (R0 to R7).

7) MOV C,31H
Answer : Direct Addressing Mode
Explanation :
In the Direct Addressing Mode, the source or destination address is specified by using 8-bit data in the instruction.
Only the internal data memory can be used in this mode.

8) AJMP 3001H
Answer : Immediate addressing mode
Explanation :
In this Immediate Addressing Mode, the data is provided in the instruction itself. The data is provided immediately after the opcode.

9) MOV A,70H
Answer : Direct Addressing Mode
Explanation :
In the Direct Addressing Mode, the source or destination address is specified by using 8-bit data in the instruction.
Only the internal data memory can be used in this mode.