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

Variance of predictions is expected to decrease, Suppose the random sample ...

Suppose the random sample used for each tree in the previous random forest is decreased from 1000 rows to 500 rows. Circle ALL that are true for the ensemble classifier. a) Vari

Optical resolution of scanner, Optical resolution or hardware resolution is...

Optical resolution or hardware resolution is mechanical limit on resolution of Scanner. For scanning the sensor has to advance after every line it scans. Smallness of this advancem

What will exactly the hide statement do, What will exactly the hide stateme...

What will exactly the hide statement do? For displaying the details on secondary lists needs that you have previously stored the contents of the selected line from within the

Advantages on electronic payment system, Advantages on electronic payment s...

Advantages on electronic payment system It gives good security schemes.  Four necessary security requirements for safe e-payments are Authentication, Encryption, Integrity,

Evaluate - 48 - 23 by using the 2's complement method, Perform the - 48 - 2...

Perform the - 48 - 23 operations using the 2's complement method. Ans. - 48 - 23 = - 48 + (-23)     -48     =  1 1 0 1 0 0 0 0     -23     =  1 1 1 0 1 0 0 1       = -71

Argument be passed to a subroutine in programming, How many ways can an arg...

How many ways can an argument be passed to a subroutine in programming? Ans)  An argument can be passed in two way in a programming language. They are Pass by Value and Passi

What are the principal shortcomings of mpi, (a) What are the principal sho...

(a) What are the principal shortcomings of MPI with respect to the deployment between companies and institutions? (b) Propose a possible solution for the parallel computing in

Make a generalize program to performs r-ary subtraction, Q. Make a genera...

Q. Make a generalize program that performs r-ary subtraction on two numbers using (r-1)'s and r's complement? Use input and output files.

Find the conversion time & conversion rate of A/D converter, Find the conve...

Find the conversion time of a Successive Approximation A/D converter which uses a 2 MHz clock and a 5-bit binary ladder containing 8V reference. What is the Conversion Rate? An

What are digital signatures and its uses, What are Digital Signatures and i...

What are Digital Signatures and its uses? A digital signature is an electronic quite than a written signature which can be used through someone to authenticate the identity of

Write Your Message!

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