Ch 05: Subroutines and Stack Architecture

Examines stack memory allocation, downward growth of the stack, return address pushing, caller vs callee register preservation, and avoiding stack misalignment bugs.

222 Questions222 MCQs0 Short Questions0 Long Questions

🎯 Exam Practice Papers

CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Timed practice exam simulation for CS401 - Computer Architecture and Assembly Language Programming.

Showing 211 – 220 of 222 Questions

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Q211

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

When encountered inside a subroutine, which instruction pops the saved return address off the stack and returns control to the instruction following the CALL?

💻 assembly Snippet

ret

A.CALL
B.RET
C.AND
D.XOR

Q212

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

Which two instructions are commonly used as a pair to invoke and return from subroutines, despite being technically independent in hardware operation?

A.RET and ADC
B.CALL and SBB
C.CALL and RET
D.ADC and SBB

Q213

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

The subroutine CALL mechanism diverts the thread of execution and preserves general-purpose registers, automatically modifying the Stack Pointer (SP) and which control register?

A.SI
B.IP (Instruction Pointer)
C.DI
D.BP

Q214

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

If the ________ instruction is not available, clearing parameters from the stack by the callee subroutine becomes a complicated process.

💻 assembly Snippet

ret 4  ; Pops return address and adds 4 to SP to clear parameters

A.CALL
B.SBB
C.RET n
D.None of the given options

Q215

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

To preserve register values across subroutine calls, the standard programming technique is to use a pair of ________ operations to save the caller's values on the stack and restore them before returning.

💻 assembly Snippet

push ax
; ... subroutine body ...
pop ax

A.POP and ADC
B.CALL and RET
C.CALL and RET n
D.PUSH and POP

Q216

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Stack Frame ArchitectureEasy🔁⭐💡📄🎓VU🏛️VU

To access caller-passed parameters from the stack inside a subroutine, the naive initial approach that comes to mind is to ________ them off the stack.

A.PUSH
B.POP
C.CALL
D.Register

Q217

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Stack Frame ArchitectureEasy🔁⭐💡📄🎓VU🏛️VU

When executing the instruction 'PUSH BP', what specific action is performed?

💻 assembly Snippet

push bp
mov bp, sp

A.Sending BP copy to stack
B.Making BP copy from stack
C.Pushing the current contents of base pointer register BP onto the stack
D.Doing nothing

Q218

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Stack Frame ArchitectureEasy🔁⭐💡📄🎓VU🏛️VU

Local variables are defined as variables whose accessibility and lifespan are strictly restricted to a specific:

💻 assembly Snippet

sub sp, 4  ; Allocate local variables on stack frame

A.Subroutine
B.Program
C.CALL
D.Label

Q219

❓ MCQ📘 CS401📑 Lec 5🏷️ 5.1. Subroutine MechanismEasy🔁⭐💡📄🎓VU🏛️VU

The CALL mechanism diverts execution control and preserves general-purpose registers, automatically modifying the Stack Pointer (SP) and which control register?

A.SI
B.IP (Instruction Pointer)
C.DI
D.SP

Q220

📝 Short Q📘 CS401📑 Lec 5🏷️ 5.1. String InstructionsEasy⭐💡📄🎓VU🏛️VU

What is the Destination Index (DI) register in 8086/8088 assembly language, and how is it used in string operations alongside the Extra Segment (ES) register?

💻 assembly Snippet

; Example string byte store using ES:DI
mov ax, 0x2000
mov es, ax      ; Load Extra Segment address into ES
mov di, 0x0100  ; Destination memory offset in DI
mov al, 'A'     ; ASCII character 'A'
stosb           ; Store byte AL into [ES:DI] and automatically increment DI

Ch 05: Subroutines and Stack Architecture

CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Mid Term Examination

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CS401 - Computer Architecture and Assembly Language Programming Examination Practice

Mid Term Examination

Final Term Examination

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