Spring 2025 COSC 2425 Chapter 4 Checkpoints Part 1

The purpose of the mov instruction in Assembly Language is to (a)  

• To add two numbers together
• To move data from one location to a
• To multiply two values
• To compare two values

Match the following fields in the modR/M byte with their roles in an xchg instruction.

• Specifies the source operand

• r/m

• Specifies the addressing mode

• mod

• Specifies the register operand

• displ

• Specifies the displacement value

• reg

What do the Flags represent in Assembly Language programming?

• Data storage locations
• Machine code representation
• Condition of the processor after an operation
• Instruction encoding format

Which instruction is used to perform subtraction in Assembly Language?

• sub
• add
• inc
• dec

What does the modR/M byte in Assembly Language encoding indicate?

• Immediate data value
• Register operations
• Data transfer instructions
• Addressing mode and operands

Which instruction is responsible for incrementing a value by 1?

• add
• mov
• inc
• neg

In Assembly Language programming, what does the neg instruction do?

• Negates the value in the accumulator
• Adds two values together
• Compares two values
• Increments a value

How are operands restricted in Assembly Language programming?

• No restrictions on operands
• Only certain registers can be used as operands
• Operands must always be immediate values
• Operands are limited by the instruction set

What is the purpose of the sub instruction in Assembly Language?

• Subtract two values
• Move data from one location to another
• Increment a value
• Normalize a value

Which field in the modR/M byte specifies the destination operand for an instruction?

• mod
• reg
• r/m
• displ