Instruction type MVI M, d8 in 8085 Microprocessor

In 8085 Instruction set, this instruction MVI M, d8 is used to load a memory location pointed by HL pair with an 8-bit value directly. This instruction uses immediate addressing for specifying the data. It occupies 2-Bytes in memory.

Mnemonics, Operand Opcode(in HEX) Bytes
MVI M, Data 36 2

As an example, we can consider MVI M, ABH as an example instruction of this type. It is a 2-Byte instruction, with opcode for MVI M using up one Byte, and ABH using up another more Byte. We are considering that HL register pair is containing 16-bit address 4050H and content of that address initially CDH. So after execution of the instruction the updated values will be

Before After
(HL) (4050) (4050)
(4050) CDH ABH

Address Hex Codes Mnemonic Comment
2006 36 MOV M, ABH Content of the memory location pointer by HL register pair will get updated by ABH
2007 AB Operand ABH

Let us check the timing diagram of this instruction MVI M, ABH


Summary − So this instruction MVI M, ABH requires 2-Bytes, 3-Machine Cycles (Opcode Fetch, Memory Read, Memory Write) and 10 T-States for execution as shown in the timing diagram.

Samual Sam
Samual Sam

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