Chapter 8_Introduction to Assembly Language

Assembly Language Programming

• low-level programming language for a computer, or other programmable device

• specific to a particular computer architecture, in contrast to most high-level programming languages

• converted into executable machine code by a utility program referred to as an assembler

• uses a mnemonic to represent each low-level machine operation or opcode.

assembler

Assembly Language Programming is converted into executable machine code by a utility program referred to as a ______

mnemonic

represent each low-level machine operation or opcode.

Opcode Mnemonics,

Data Sections,

Assembly Directives

Language Design: 3 types of instruction statements

Opcode mnemonics and extended mnemonic

a symbolic name for a single executable machine language instruction and there is at least one opcode mnemonic defined for each machine language instruction.

Data directives

pseudo-ops

pseudo-ops

• used to define data elements to hold data and variables

• define the type of data, the length and the alignment of data

• define whether the data is available to outside programs

Assembly directives

pseudo opcodes

pseudo opcodes

instructions that are executed by an assembler at assembly time, not by a CPU at run time

Symbolic assemblers

let programmers associate arbitrary names (labels or symbols) with memory locations

Macros

• involving sequences of text lines in which variables and constants are embedded

• Macro assemblers often allow _____ to take parameters

Need

Each type of CPU has its own machine language and assembly language

Historical perspective,

Current usage

Use of assembly language (2)

Historical perspective

Assembly languages date to the introduction of the stored program computer

EDSAC computer (1949)

has an assembler called initial orders with one-letter mnemonics

Nathaniel Rochester (1954)

wrote an assembler for IBM 701

SOAP (Symbolic Optimal Assembly Program) (1955)

assembly language for IBM 650 (Stan Poley)

microcomputers

1980s (1990s on _____)

Current usage

• Assembly language has specific niche uses where it is important modern

• optimizing compilers are claimed to render high- level languages into code that can run as fast as hand-written assembly

• Typical applications

  • Some compilers translate high-level languages into assembly

  • Relatively low-level languages, such as C

  • Assembly language is valuable in reverse engineering

  • Assemblers can be used to generate blocks of data

translate high-level languages,

low-level languages,

reverse engineering,

generate blocks of data

Current usage

• Typical applications

  • Some compilers _____ into assembly

  • Relatively _____, such as C

  • Assembly language is valuable in _____

  • Assemblers can be used to _____

Input/Output (I/O) Instructions

used to input data from peripherals, output data to peripherals, or read/write input/output controls

IN Input; MIX,

OUT Output; MIX,

IOC Input-Output Control; MIX,

JRED Jump Ready; MIX,

JBUS Jump Busy; MIX,

Input/Output (I/O) Instructions (5)

Integrated Development Environment

• to develop, assemble, and deploy Java Platform, Enterprise Edition (Java EE) modules

• for WebSphere® Application Server.

IBM® Rational® Application Developer

for WebSphere Software product

IBM WebSphere Application Server Developer Tools

for Eclipse product

IBM Assembly and Deploy Tools

for WebSphere Administration product

Interfacing assembly with HLL

• There are times that high level languages need to call assembly language modules.

• This results due to constraints like speed and memory space.