The addressing mode in which the data operand is a part of the instruction itself is known as immediate addressing mode. Register indirect addressing This addressing mode allows data to be addressed at any memory location through an offset address held in any of the following registers: BP, BX, DI & SI. The addressing mode help us in identifying the source of the operand or calculate the offset of the operands if it is in memory. The addressing mode of 8086 is divided in two categories: Data related addressing modes: It is used for data access from /to different source and destinations. Addressing modes are used to specify the address of the data or data in instructions. It is basically the way of specifying data in instruction. There are various such ways, addressing modes for data memory: Immediate Addressing Mode; In this mode the operand is specified in the instruction itself. Address modes are simple variants of one another so they're very easy to learn. The addressing modes provided by the 8086 family include displacement-only, base, displacement plus base, base plus indexed, and displacement plus base plus indexed. Variations on these five forms provide the 17 different addressing modes on the 8086.
Register Addressing
In register addressing the instruction will specify the name of the register which holds the data to be operated by the instruction.
Addressing Modes Of 8086 Mcq
Immediate Addressing
In immediate addressing mode an 8-bit or 16-bit data is specified as part of the instruction.
Direct Addressing
In direct addressing an unsigned 16-bit displacement of signed 8-bit displacement will be specified in the instruction.The displacement is the effective address(EA) or offset.The 20 bit physical address of memory is calculated by multiplying the content of DS register by 10H and adding to effective address.In case of 8-bit displacement, the effective address is obtained by sign extending the 8-bit displacement to 16-bit.
The segment base address (BA) is computed by multiplying the content of DS by 16(base 10)The memory address (MA) is computed by adding the effective address (EA) to the segment base address (BA)
Register Indirect Addressing
In register indirect adddressing the name of the register which holds the effective address(EA)will be specified in the instructionThis addressing mode allows data to be addressed at any memory location through an offset address held in any of the following registers: BP, BX, DI & SI.
Addressing Modes Of 8086 Microprocessor Pdf
This instruction moves a word from the address pointed by BX and BX + 1 in data segment into CL and CH respectively.
Based Addressing Mode
In this addressing mode, the offset address of the operand is given by the sum of contents of the BX/BP registers and 8-bit/16-bit displacement.
Indexed Addressing Mode
In this addressing mode, the operands offset address is found by adding the contents of SI or DI register and 8-bit/16-bit displacements.