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
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.
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
The set of instructions that tells the computer how to perform a particular task is called a "computer program" or "software." These instructions are typically written in a programming language such as Python, Java, or C++. The program is then executed by the computer's processor, following the specified sequence of operations to achieve the desired outcome.
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.
In programming, the term "atomic" refers to an operation that is indivisible and cannot be interrupted. This impacts the execution of code by ensuring that certain operations are completed without interference from other processes, which helps maintain data integrity and prevent race conditions.
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)
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.
popfd
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
An opcode is an instruction. An operand is information used by the opcode. Not all opcodes require operands.
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.
IP is incremented after fetch of instruction opcode. Specifically, IP is incremented by the number of opcode bytes.
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.
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.
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.
The hard way: Download the processor manuals and code the opcode and operands by hand The easy way: Use an assembler program. The instructions are slightly different for each program, so try reading the manuals.
It is partial with opcode and processor code. It is meaningless when we see it on our eyes, but it provides info instructions to Java Virtual Machine to execute that.