UNIT 2 PROGRAMMING IN 8086-S1

What is the purpose of addressing modes in 8086 assembly?

• To provide flexibility in accessing operands and optimize instruction execution.

• To enhance the security of the code.

• To simplify the instruction set architecture.

• To limit the number of available registers.

List three types of data transfer instructions in 8086.

• ADD

• SUB

• MOV, PUSH, POP

• MUL

Explain the difference between arithmetic and logical instructions.

• Arithmetic instructions perform string manipulations, whereas logical instructions are for numerical comparisons.

• Arithmetic instructions are used for data storage, while logical instructions are for memory management.

• Arithmetic instructions are only applicable in programming languages, while logical instructions are used in hardware design.

• Arithmetic instructions handle numerical calculations, while logical instructions manage boolean operations.

What is the function of branch instructions in assembly language?

• The function of branch instructions is to change the flow of execution in a program.

• To initialize variables.

• To store data in memory.

• To perform arithmetic operations.

Describe how loop instructions work in 8086 assembly.

• Loop instructions in 8086 assembly increment the CX register and repeat execution until CX is one.

• Loop instructions in 8086 assembly do not affect the CX register and run only once.

• Loop instructions in 8086 assembly are used to jump to a random memory address without checking CX.

• Loop instructions in 8086 assembly decrement the CX register and repeat execution until CX is zero.

What is a 'While' loop and how is it implemented in 8086?

• A 'While' loop is a type of interrupt in 8086 programming.

• In 8086, a 'While' loop is implemented using conditional jumps (like JZ, JNZ) and labels to control the flow based on a condition.

• In 8086, 'While' loops are created with nested procedures only.

• A 'While' loop is implemented using a single GOTO statement.

Define a 'Do' loop and provide an example in assembly language.

• A 'Do' loop is a type of loop that only runs once.

• Example in assembly language: section .data count db 0 section .text global _start _start: ; Do loop starts here mov al, [count] inc al mov [count], al cmp al, 5 jl _start ; Jump back to start if count < 5 ; Exit program mov eax, 60 ; syscall: exit xor edi, edi ; status: 0 syscall This example increments a counter until it reaches 5.

• Example in assembly language: mov eax, 10; sub eax, 1; jnz _start;

• A 'Do' loop is used to create a static array in assembly language.

What are strings in the context of 8086 assembly programming?

• Strings in 8086 assembly are sequences of characters stored in memory, terminated by a null character.

• Strings are only used for numeric data in 8086 assembly.

• Strings in 8086 assembly are sequences of bytes without any termination.

• Strings are fixed-length arrays of integers in 8086 assembly.

How do you declare a procedure in 8086 assembly?

• Use 'PROC' to start and 'ENDP' to end the procedure.

• Declare with 'FUNCTION' and close with 'END' in 8086 assembly.

• Use 'BEGIN' to start and 'FINISH' to end the procedure.

• Start with 'SUBROUTINE' and end with 'RETURN' for procedures.

What is the significance of macros in assembly language?

• Macros enable code reuse and simplification in assembly language.

• Macros are only applicable in high-level programming languages.

• Macros are a type of data structure in assembly language.

• Macros are used to increase the execution speed of assembly programs.