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an opcode (operation code) is the portion of a machine language instruction that specifies the operation to be performed. Their specification and format are laid out in the instruction set architecture of the processor in question (which may be a general CPU or a more specialized processing unit). Apart from the opcode itself, an instruction normally also has one or more specifiers foroperands (i.e. data) on which the operation should act, although some operations may have implicit operands, or none at all. There are instruction sets with nearly uniform fields for opcode and operand specifiers, as well as others (the x86architecture for instance) with a more complicated, varied length structure.
by: HerLoyd
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What is expanding opcode?
A code that leaves a spare bit to indicate that if that bit is set, consider this byte and the next byte to be defining the entire code.
What is the set of instructions that tells the computer how to perform a particular task?
Instruction down to hardware level break down toOpcode ( Operation Code ) followed by Operands ( Data onto which such operation is to be performed )Collection/Series of these Opcode + Operands help in performing a particular task - Thus a small Program is created.
What are the basic features of assembly language?
Symbols to represent instructions Each instruction (opcode) is given some mnemonic name Various addressing modes might select different opcodes for same mnemonic Symbols to represent labels and variables The addresses where variables are stored can be named Addresses in the code can be labelled
How are instructions given to a computer?
An extremely simple thing called machine code. Im not insulting you with the extremely simple thing, that just means its easy for the computer to follow. Machine code tells the computer what to do and when to do it.
What are the typical elements of machine instruction?
Operation code, source operand reference, result operand reference, and next instruction reference. (source: Computer organization and architercture eighth edition by William Stallings)
What is use of registers?
It holds the operation code .that is the opcode of the current instruction of the program during the arithmatic and logic operation......it is also called single cycle execution(only one perform)
Which part of the instruction tells the microprocessor what operation is to be performed?
The part of the instruction that tells a computer what operation to perform is variously called the "operation code", "op code", "opcode", "operation", "order code", "instruction code", "function designator", "function", "prefix", "designator", etc. depending on the specific computer and the (arbitrary) preferences of the designers of that computer architecture about terminology. Some computers have special instructions that use parts of the instruction in a different way than other instructions do to provide additional operations (e.g. PDP-8 in the OPR instruction used the fields used by most other instructions for memory addressing as a "microcoded" operation request, PowerPC has "primary opcode" and an optional "extended opcode"). There are some computer architectures that do not even use instructions (e.g. dataflow computers) or have instructions without an opcode (e.g. Transport Triggered Architectures, Forth virtual machine) but they are still fairly rare.
What is operation code?
an opcode (operation code) is the portion of a machine language instruction that specifies the operation to be performed. Their specification and format are laid out in the instruction set architecture of the processor in question (which may be a general CPU or a more specialized processing unit). Apart from the opcode itself, an instruction normally also has one or more specifiers foroperands (i.e. data) on which the operation should act, although some operations may have implicit operands, or none at all. There are instruction sets with nearly uniform fields for opcode and operand specifiers, as well as others (the x86architecture for instance) with a more complicated, varied length structure.by: HerLoyd
How do you convert opcode to machine code?
popfd
What are the difference between opcode and operand?
What is difference between oppress code and operend
CPU does not distinguish data and operation code explain?
As far as the bus interface is concerned, there is no real difference between data and instructions. Except for the S0 pin, an opcode fetch will look the same as a memory read. There is one extra clock cycle following an opcode fetch, which is used by the CPU to decode and process the opcode, but the bus does not care because there is no sequence initiation with ALE.
What happens to ip after completion of fetch of instruction code?
IP is incremented after fetch of instruction opcode. Specifically, IP is incremented by the number of opcode bytes.
How does microprocessor differentiate between data and instruction code?
i) Instruction code deals only with mnemonics and its corresponding opcode but data code refers to your data like 10h which is always of 8 bits or a particular address say 8080h which is of 16 bits. ii) Data is your input to the instruction but an opcode is native to your machine. iii) Data is user specific instruction while opcode is machine specific instruction iv) You can alter data code but you cannot modify an instruction opcode.
How an assembler converts assembly mnemonics to machine language?
Each mnemonic maps directly to a machine instruction code, known as an opcode. Some mnemonics map to more than one opcode, however the instruction's operand types will determine which specific opcode will be generated.
What is expanding opcode?
A code that leaves a spare bit to indicate that if that bit is set, consider this byte and the next byte to be defining the entire code.
What are operands?
Every instruction contains to parts: operation code[opcode],and operand. The first part of an instruction which specifies the task to be performed by the computer is called opcode. The second part of the instruction is the data to be operated on.,and it is called operand. The operand[or data]given in the instruction may be in various forms such as 8-bit or 16-bit data, 8-bit or 16-bit address, internal register or a register or memory location.
What translates a program written in Assembly language into machine code?
Well, let's say you have the following Assembler statement: MOV AX, 0005 Each processor (depending on the processor architecture, being some of them: SPARC, Intel 80x86, Motorola...) translates each Assembler mnemonic and register into Machine Code according to an Opcode Table. Think of an Opcode Table this way: Instruction OpCode ----------------------------------- MOV A1 ADD A2 SUB A3 MUL A4 DIV A5 ... AX B0 BX B1 CX B2 ... Each mnemonic/register has its corresponding hex code for the processor to understand the operation, so: MOV AX, 0005 Could be translated as: A1 B0 0005 Hopefully this gives you an idea of how a processor assembles code and generates machine code.
