Register Indirect Mode in 8085 Microprocessor
The register indirect mode in the 8085 microprocessor is the addressing mode in which the register specifies the effective address of the operand. In other words, in the register indirect mode in the 8085 microprocessor, the operand is present in the address specified in the register in the instruction. In this addressing mode, the address of the operand is specified indirectly by using the register.
8085 Microprocessor Instruction with Register Indirect Mode
Representation of 8085 microprocessor instruction with register indirect addressing modes.
Opcode Destination Operand, Source Operand |
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Opcode Register, Register |
Operations on Register Indirect Addressing Mode
In register indirect addressing mode, we require following operations to fetch the operand.
- First identify the register from the specified address in the instruction.
- Then, go to the register and get the content of the register which gives us the effective address of the operand.
- Then, go to the specified effective address.
- The content present in the effective address gives us the operand on which operations is to be performed.
Examples of 8085 Microprocessor Instruction with Register Indirect Mode
Some examples of register indirect addressing modes in 8085 microprocessors are given below.
Instructions of 8085 microprocessor (register indirect addressing mode used) |
Description |
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MOV A, M |
This instruction stores the data present in the address specified in the H-L registers to the accumulator. |
LDAX B |
This instruction stores the content of the address specified in the BC register to the accumulator. |
STAX B |
This instruction stores the content of the accumulator to the memory address specified by the BC register. |
Register indirect addressing mode in 8085 Microprocessor
Register indirect mode in 8085 microprocessors is an addressing mode in which the address part of the instruction specifies the address of the register, and the register holds the effective address of the operand. The operand is present in the effective address specified by the register. In this article, we will explore register indirect addressing mode in 8085 microprocessors in detail along with examples. Also, we will discuss the advantages and disadvantages and applications of register indirect addressing modes.