Assembly Language Programming

Questions and Answers

What operation does the LOAD command perform?

Places the contents of LOC into the ACC while leaving LOC unchanged. (correct)

Multiplies the ACC by the contents of LOC.

Stores the contents of the ACC at the location LOC.

Adds the contents of LOC to the ACC.

What happens to the contents of the ACC after an ADD operation?

The sum of LOC and ACC is stored in LOC.

The sum of LOC and ACC is stored in the ACC, with addition modulo 1,000,000. (correct)

The contents of LOC are unchanged.

The contents of LOC are added to the ACC and stored in LOC.

During a SUB operation, what is the result that is stored in the ACC?

The negative of the contents of LOC.

The difference calculated modulo 1,000,000. (correct)

The contents of LOC subtracted from zero.

The difference between the contents of LOC and ACC, using standard subtraction.

In a DIV operation, what part of the result is stored in the ACC?

The signed integer part of the quotient. Signup and view all the answers

Which condition will trigger a branch operation using the BE command?

When the ACC is exactly zero. Signup and view all the answers

What is the purpose of assembly language in programming?

It helps programmers understand the behavior of high-level compilers. Signup and view all the answers

What does the accumulator (ACC) store in an assembly language program?

It stores the result of each operation performed in the program. Signup and view all the answers

What is the function of the LABEL field in an assembly language instruction?

It provides a case-sensitive identifier for referencing in programs. Signup and view all the answers

Which of the following is true about opcodes in assembly language?

They are reserved words that must be in uppercase. Signup and view all the answers

What occurs if an END instruction is not encountered during execution?

The program will enter an infinite loop. Signup and view all the answers

What happens when the instruction 'LOAD =123' is executed?

The ACC will contain the immediate value of 123. Signup and view all the answers

Which statement about the LOC field is correct?

It can refer to either a label or immediate data. Signup and view all the answers

What is the initial value of the accumulator (ACC) in an assembly language program?

0 Signup and view all the answers

Study Notes

Assembly Language Programming Overview

High-level languages are converted into assembly language by compilers, which are further turned into machine language by assemblers.
Understanding assembly language is crucial for programmers to grasp compiler constraints and to optimize for speed or memory use.
ACSL developed its own simplified assembly language framework to avoid complexities associated with actual assembly languages.

Program Execution

Execution starts at the program's first line and continues sequentially until the END instruction is reached.
Program results are stored in an "accumulator" (ACC), which starts with an initial value of 0.

Program Structure

Each assembly language program line consists of three fields: LABEL, OPCODE, and LOC.
LABEL: An optional alphanumeric string, case-sensitive, starting with an alphabetic character.
OPCODE: Reserved uppercase words (case-sensitive) denoting operations, cannot be used as labels.
LOC: Can be either a reference to a label or immediate data.

Instruction Functions

LOAD: Stores the contents of LOC in ACC; LOC remains unchanged.
STORE: Transfers contents of ACC to LOC; ACC remains unchanged.
ADD: Adds content of LOC to ACC; the sum is stored in ACC (modulo 1,000,000) while LOC remains unchanged.
SUB: Subtracts contents of LOC from ACC; the difference is stored in ACC (modulo 1,000,000) with LOC unchanged.
MULT: Multiplies the contents of LOC by ACC; product is stored in ACC (modulo 1,000,000) while LOC remains intact.
DIV: Divides the ACC by contents of LOC; signed integer part of the quotient is stored in ACC with LOC unchanged.

Branch Instructions

BG (Branch Greater): Branch to labeled instruction if ACC > 0.
BE (Branch Equal): Branch if ACC = 0.
BL (Branch Less): Branch if ACC < 0.

Description

This quiz explores the fundamental concepts of assembly language programming and its significance in the conversion of high-level languages into machine code. Understanding assembly language is crucial for programmers despite the prevalence of advanced compilers. Test your knowledge on the basics and applications of assembly language.