Assembly language - computer architecture, Computer Engineering

Assignment Help:

Assembly language:

An assembly program has a series of instructions--mnemonics that relate to a stream of executable instructions, when translated by an assembler that may be loaded into memory and then executed.

For an example, an x86/IA-32 processor may execute the following binary instruction as expressed in machine language (see x86 assembly language):

  • Binary: 10110000 01100001 (Hexadecimal: B0 61)

The equivalent assembly language representation is simpler to remember (example in the Intel synta x, more mnemonic):

  • MOV AL, 61h

Means of this instruction:

  • Move the value 61h (or 97 decimal; the h-suffix means hexadecimal; into the processor register named "AL".

The mnemonic "mov" represents the opcode 1011 which moves the value in the second operand into the register specified by the first operand. The mnemonic was selected by the instruction set designer to abbreviate "move", by making it easier for the programmer to remember.  A comma-separated list of parameters or arguments follows the opcode; it is a typical assembly language statement.

In practice many programmers drop the word mnemonic and which is technically incorrect, call "mov" an op code. When they do this they are referring to the underlying binary code which it represents. To put it as a way, a mnemonic such as "mov" is not an op code, but it symbolizes an op code, one can refer to "the op code mov" for instance when one intends to refer to the binary op code it symbolizes rather than to the symbol -- the mnemonic -- itself. As few modern programmers have required being attentive of actually what binary patterns are the op codes for specific instructions, the distinction has in practice become a bit blurred among programmers but not among processor designers.

An assembler transforms assembly language into machine language, and the reverse by disassemble. There is typically a one-to-one correspondence between assembly statements unlike in high-level languages, and the machine language instructions. But, in some cases, an assembler can provide pseudo instructions which expand into various machine language instructions to provide commonly required functionality. For instance, for a machine that lacks a "branch if greater or equal" instruction, an assembler can be used a pseudo instruction that expands to the machine's "branch if zero (on the result of the set instruction)"and "set if less than" and. All the full-featured assemblers also provide a rich macro language mostly (discussed below) which is used by programmers and vendors to generate more difficult code and data sequences.

Each processor architecture and computer architecture has its own machine language. On this level, each instruction is enough simple to be executed by using a relatively small number of electronic circuits. Computers differ by the type and number of operations they support. For instance, a new 64-bit machine would have different circuitry from a 32-bit machine. They can also have different sizes and numbers of registers and different representations of data types in storage. Whereas most general-purpose computers are able to carry out really the same functionality, the ways they do so differ; the equivalent assembly languages reflect these differences.

Multiple sets of assembly-language syntax or mnemonics may exist for a single instruction set, typically instantiated in different assembler programs. In these types of cases, the most popular one is usually that supplied by the manufacturer and used in its documentation.


Related Discussions:- Assembly language - computer architecture

Define input-output interface, Define Input-Output Interface. I/O inter...

Define Input-Output Interface. I/O interface gives a method for transferring information among internal storage and external I/O devices

Explain non-folded network, Explain Non-Folded network Non-Folded Netw...

Explain Non-Folded network Non-Folded Network: In a switching network, every inlet/outlet connection may be utilized for inter exchange transmission. In this case, the .excha

What is rolap, Functioning of ROLAP happens concurrently with relational da...

Functioning of ROLAP happens concurrently with relational databases. Data and tables are stored as relational tables. To hold new information or data new tables are formed. Functio

Feature Extraction and clustering, Hi, It is a data mining project I have ...

Hi, It is a data mining project I have a CSV file that has numbers data set. The data set contains images of handwritten digits. Recognizing handwritten digits is already a mature

Determine the two input of NOR gate if output will be low, The NOR gate out...

The NOR gate output will be low if the two inputs are ? Ans. Output is low if any of the input is high means input may be 01,10 or 11.

Padovan string , A Padovan string P(n) for a natural number n is defined as...

A Padovan string P(n) for a natural number n is defined as: P(0) = ‘X’ P(1) = ‘Y’ P(2) = ‘Z’ P(n) = P(n-2) + P(n-3), n>2 where + denotes string concatenation. For a string of t

Coso framework, The COSO Framework consists of six broad classes of control...

The COSO Framework consists of six broad classes of control activities. Initial responses should identify and define one of the broad classes (Ex: segregation of duties or indepe

Why do we need dma, Why do we need DMA? DMA is used to transfer the blo...

Why do we need DMA? DMA is used to transfer the block of data directly among an external device and the main memory without the continuous intervention by the processor.

What is random access memory, Q. What is Random Access Memory? We will ...

Q. What is Random Access Memory? We will discuss RAM as an example of sequential circuit. A memory unit is a collection of storage cells or flip flops along with associated cir

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd