ADDRESSING MODES OF 80386 PROCESSORS

The 80386  addressing modes to facilitate efficient execution higher level language programs. The 80386 has all the addressing modes which were available with 80286. Besides these, 80386 have a family of scaled modes. In the case of scaled modes, any of the index register values can be multiplied by a valid scale factor to obtain the displacement. The valid scale factors are 1,2, 4, and 8. 1. Scaled Indexed Mode: The contents of an index register are multiplied by a scale factor that may be added further to get the operand offset. Ex. MOV EBX, LIST [ESI* 2] MUL ECX, LIST [EBP*4] 2. Based Scaled Indexed mode: The contents of an index register are multiplied by a scale factor and then added to base register to obtain the offset. Ex: MOV EBX, [EDX*4] [ECX] MOV EAX, [EBX*2] [ECX] 3. Based scaled indexed mode with displacement: the contents of an index register are multiplied by a scale factor and the result is added to a base register and a displacement to get the offset of an operand. Ex: MOV EAX, LIST [ESI* 2] [EBX+0800] MUL EBX, LIST [EDI*8] [ECX+0100].

''''''''''''''''Culture is the widening of the mind and of the spirit.''''''''

 @NEHRU