addressing mode

[ə′dres·iŋ ‚mōd] (computer science) The specific technique by means of which a memory reference instruction will be spelled out if the computer word is too small to contain the memory address.

addressing mode

(processor, programming)One of a set of methods forspecifying the operand(s) for a machine code instruction.Different processors vary greatly in the number of addressingmodes they provide. The more complex modes described belowcan usually be replaced with a short sequence of instructionsusing only simpler modes.

The most common modes are "register" - the operand is storedin a specified register; "absolute" - the operand is storedat a specified memory address; and "immediate" - the operandis contained within the instruction.

Most processors also have indirect addressing modes, e.g."register indirect", "memory indirect" where the specifiedregister or memory location does not contain the operand butcontains its address, known as the "effective address". Foran absolute addressing mode, the effective address iscontained within the instruction.

Indirect addressing modes often have options for pre- or post-increment or decrement, meaning that the register or memorylocation containing the effective address is incremented ordecremented by some amount (either fixed or also specified inthe instruction), either before or after the instruction isexecuted. These are very useful for stacks and foraccessing blocks of data. Other variations form the effectiveaddress by adding together one or more registers and one ormore constants which may themselves be direct or indirect.Such complex addressing modes are designed to support accessto multidimensional arrays and arrays of data structures.

The addressing mode may be "implicit" - the location of theoperand is obvious from the particular instruction. Thiswould be the case for an instruction that modified aparticular control register in the CPU or, in a stack basedprocessor where operands are always on the top of the stack.

addressing mode

(2)In IBM System 370/XA the addressing mode bit controlsthe size of the effective address generated. When this bitis zero, the CPU is in the 24-bit addressing mode, and 24 bitinstruction and operand effective addresses are generated.When this bit is one, the CPU is in the 31-bit addressingmode, and 31-bit instruction and operand effective addressesare generated.

["IBM System/370 Extended Architecture Principles ofOperation", Chapter 5., 'Address Generation', BiModalAddressing].

单词	addressing mode
释义	addressing mode addressing mode [ə′dres·iŋ ‚mōd] (computer science) The specific technique by means of which a memory reference instruction will be spelled out if the computer word is too small to contain the memory address. addressing mode (processor, programming)One of a set of methods forspecifying the operand(s) for a machine code instruction.Different processors vary greatly in the number of addressingmodes they provide. The more complex modes described belowcan usually be replaced with a short sequence of instructionsusing only simpler modes. The most common modes are "register" - the operand is storedin a specified register; "absolute" - the operand is storedat a specified memory address; and "immediate" - the operandis contained within the instruction. Most processors also have indirect addressing modes, e.g."register indirect", "memory indirect" where the specifiedregister or memory location does not contain the operand butcontains its address, known as the "effective address". Foran absolute addressing mode, the effective address iscontained within the instruction. Indirect addressing modes often have options for pre- or post-increment or decrement, meaning that the register or memorylocation containing the effective address is incremented ordecremented by some amount (either fixed or also specified inthe instruction), either before or after the instruction isexecuted. These are very useful for stacks and foraccessing blocks of data. Other variations form the effectiveaddress by adding together one or more registers and one ormore constants which may themselves be direct or indirect.Such complex addressing modes are designed to support accessto multidimensional arrays and arrays of data structures. The addressing mode may be "implicit" - the location of theoperand is obvious from the particular instruction. Thiswould be the case for an instruction that modified aparticular control register in the CPU or, in a stack basedprocessor where operands are always on the top of the stack. addressing mode (2)In IBM System 370/XA the addressing mode bit controlsthe size of the effective address generated. When this bitis zero, the CPU is in the 24-bit addressing mode, and 24 bitinstruction and operand effective addresses are generated.When this bit is one, the CPU is in the 31-bit addressingmode, and 31-bit instruction and operand effective addressesare generated. ["IBM System/370 Extended Architecture Principles ofOperation", Chapter 5., 'Address Generation', BiModalAddressing]. See AMODE See AMODE
随便看	european competition law review european competition lawyers forum european competition network european competitive telecommunications association european compliance inspection program european composite unit european computational aerodynamics research project european computer driving licence european computer driving licence advanced european computer driving licence foundation ltd. european computer driving license european computer industry research centre european computer-industry research centre european computer-industry research centre gmbh european computer leasing & trading association european computer manufacturer's association european computer manufacturers association european computer network for the arts european computer science european computer science summit european computer solutions and trading european computer supported cooperative work conference european computer telecoms european computer trade show european computer vision network