Relative Based Indexed Addressing mode: In this mode, 8-bit or 16-bit instruction operand is added to the contents of a base register (BX or BP) and index register (SI or DI), the resulting value is a pointer to location where data resides.Įxample: MOV AX, 50H 2.Based Indexed Addressing mode: In this mode, the contents of a base register (BX or BP) is added to the contents of an index register (SI or DI), the resulting value is a pointer to location where data resides.Register Relative Addressing mode: In this mode, the data is available at an effective address formed by adding an 8-bit or 16-bit displacement with the content of any one of the registers BX, BP, SI, DI in the default segments.DS and ES are default segments for index registers SI and DI. Indexed Addressing mode: 8-bit or 16-bit instruction operand is added to the contents of an index register (SI or DI), the resulting value is a pointer to location where data resides.This addressing mode works with SI, DI, BX and BP registers. Register Indirect addressing mode: In this mode, instruction specifies a register containing an address, where data is located.All the registers except IP may be used in this mode. Register Addressing mode: In this mode, the data is stored in a register and it is referred using particular register.Effective Address (EA) is computed using 5000H as offset address and content of DS as segment address.
In this type of instruction after execution control can be transferred to the next immediately appearing instruction in the program.
Thus the addressing modes describe the types of operands and the way they are accessed for executing an instruction.Īccording to the flow of instruction execution, the instruction may be categorized as: Depending upon the data types used in the instruction and the memory addressing modes, any instruction may belong to one or more addressing modes. Addressing modes indicates way of locating data or operands.
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