Chap 6 CS AS Level

Machine code instruction

• A single operation performed by a CPU.

• A binary code with a defined number of bits that comprises an opcode and, most often, one operand

• Mode of addressing in which the value of the operand only is used.

• Mode of addressing in which the contents of the memory location in the operand are used.

Opcode

• Defines the action associated with the instruction

• A low-level chip/machine specific programming language that uses mnemonics.

• The complete set of machine code instructions used by a CPU.

• A computer program before translation into machine code.

Assembly language

• A computer program after translation into machine code.

• A low-level chip/machine specific programming language that uses mnemonics.

• The complete set of machine code instructions used by a CPU.

• A computer program before translation into machine code.

Operand

• The complete set of machine code instructions used by a CPU.

• A computer program before translation into machine code.

• A computer program after translation into machine code.

• Defines any data needed by the instruction

Directive

• A computer program before translation into machine code.

• An instruction to the assembler program

• A program used to translate an assembly language program into machine code

• Defines the action associated with the instruction

Assembler

• Mode of addressing used in assembly language programming, where a label is used instead of a value.

• A program used to translate an assembly language program into machine code

• Mode of addressing in which the memory address used is the current memory address added to the operand.

• Mode of addressing in which the contents of the memory location found by adding the contents of the index register (IR) to the address of the memory location in the operand are used.

Addressing mode

• Mode of addressing in which the contents of the contents of the memory location in the operand are used.

• When the instruction uses a value this defines how the operand must be used to find the value

• Mode of addressing in which the memory address used is the current memory address added to the operand.

• Mode of addressing used in assembly language programming, where a label is used instead of a value.

Relative Addressing

• Mode of addressing in which the contents of the contents of the memory location in the operand are used.

• When the instruction uses a value this defines how the operand must be used to find the value

• Mode of addressing in which the memory address used is the current memory address added to the operand.

• Mode of addressing used in assembly language programming, where a label is used instead of a value.

Symbolic Addressing

• Mode of addressing in which the contents of the contents of the memory location in the operand are used.

• When the instruction uses a value this defines how the operand must be used to find the value

• Mode of addressing in which the memory address used is the current memory address added to the operand.

• Mode of addressing used in assembly language programming, where a label is used instead of a value.

Indirect addressing

• Mode of addressing in which the contents of the contents of the memory location in the operand are used.

• When the instruction uses a value this defines how the operand must be used to find the value

• Mode of addressing in which the memory address used is the current memory address added to the operand.

• Mode of addressing used in assembly language programming, where a label is used instead of a value.