Binary Operations in Assembly Language

Questions and Answers

What does the symbol '#' in 'AND.B #$C0,DO' do?

Represents a label in the assembly program

Specifies the immediate addressing mode (correct)

Informs the assembler that the following value is an address

Indicates the following value is a hexadecimal number

What is the purpose of the label 'FALSE' in the given assembly code?

It is used to specify a branch target

It is a dummy label that is not used by the assembly program (correct)

It is used to skip over unused code

It serves as a reminder to the programmer of the action to be taken when a test is false

What is the effect of the instruction 'AND.B #%11000000,DO'?

It performs a logical AND operation between the binary value 11000000 and the contents of DO, and stores the result in DO

It performs a logical AND operation between the binary value 11000000 and the contents of DO, and discards the result (correct)

It loads the binary value 11000000 into DO

It stores the result of the logical AND operation in a memory location

What is the equivalent of 'BRA EXIT' in a high-level language?

GOTO Signup and view all the answers

What is the addressing mode used in the instruction 'MOVE NUM,D0'?

Immediate addressing Signup and view all the answers

What is the purpose of the 'MOVE' instruction in assembly language programming?

To load or store data Signup and view all the answers

What is the effect of the instruction 'AND.B #192,DO'?

It performs a logical AND operation between the decimal value 192 and the contents of DO, and stores the result in DO Signup and view all the answers

What is one of the major goals of computer science?

To use abstraction to insulate the users from how the computer works Signup and view all the answers

What is the purpose of the 'BRA' instruction in assembly language programming?

To control program flow Signup and view all the answers

What is the ultimate goal of learning assembly language?

To directly manipulate the hardware Signup and view all the answers

What is a benefit of abstraction in computer science?

It allows users to perform complex tasks without knowing how the computer works Signup and view all the answers

What is the relationship between high-level languages and assembly language?

High-level languages are translated into assembly language to use the hardware Signup and view all the answers

What is a key difference between assembly language and high-level languages?

Assembly language directly manipulates the hardware Signup and view all the answers

What is the purpose of the AND.B instruction?

To test the value of specific bits in the input Signup and view all the answers

Why is understanding computer hardware important for computer professionals?

So they can fill gaps in their abilities as programmers or system administrators Signup and view all the answers

What is the function of the CMP.B instruction?

To test the value of specific bits in the input Signup and view all the answers

What is the focus of assembly language programming?

Specifying exactly how the hardware should work Signup and view all the answers

What is the purpose of the BEQ instruction?

To branch to a label if the test is true Signup and view all the answers

What do high-level languages abstract and hide from users?

The underlying hardware Signup and view all the answers

What is the difference between the CMP and SUB instructions?

CMP evaluates the difference between the operands, while SUB stores the result in the destination Signup and view all the answers

What is the purpose of the MOVE.B instruction?

To move data between registers or memory locations Signup and view all the answers

What is the symbol % used for in assembly language?

To indicate the following operand is hexadecimal Signup and view all the answers

What is the purpose of the control flow instructions in the algorithm?

To test the value of specific bits in the input and branch accordingly Signup and view all the answers

What is the purpose of the addressing mode used in the MOVE.B instruction?

To specify the register or memory location to be accessed Signup and view all the answers

Study Notes

Binary Numbers and Operations

In assembly language, numbers can be interpreted as binary values using the % symbol, e.g., %#11000000.
The AND instruction performs a logical AND operation between the binary value and the contents of a register or memory location.
The # symbol informs the assembler that the following value is not an address of a memory location, but the value itself.

Assembly Language Programming

Assembly language is used to directly manipulate the hardware, giving the programmer control over how the hardware works.
It does not rely on abstraction, unlike High-Level Languages (HLL), and uses a different vocabulary.
Assembly language is translated into machine code that the computer's hardware can execute.

Addressing Modes

Immediate addressing is used to specify an arithmetic constant as an operand.
The MOVE instruction can be used to load a value into a register, e.g., MOVE NUM, D0.
The BRA instruction is equivalent to a GOTO in a high-level language and causes a branch to a labeled instruction.

Conditional Statements

Conditional statements are used to test conditions and branch to specific instructions based on the result.
The CMP instruction is used to compare the contents of a register or memory location with a value.
The BEQ instruction branches to a labeled instruction if the comparison result is equal.

Registers and Flags

The Condition Code Register (CCR) contains flags that are set based on the result of arithmetic and logical operations.
The Z (zero) flag is set if the result of a subtraction is zero.
The bits of the CCR are modified by certain instructions, such as CMP and SUB.

68K Assembly Language

The 68K assembly language is used to program the 68000 microprocessor.
The language uses a specific syntax and vocabulary to specify instructions and operands.
The MOVE.B instruction is used to move a byte-sized value into a register or memory location.