GATE CSE 2023 Paper 1 — page 14

Questions 40–42 of 65. Imported answers require review unless explicitly marked reviewed.

Consider the pushdown automaton (PDA)

below, which runs on the input alphabet

, has stack alphabet

, and has three states

, with

being the start state. A transition from state

to state

, labelled

, where

is an input symbol or

is a stack symbol, and

is a string of stack symbols, represents the fact that in state

, the PDA can read

from the input, with

on the top of its stack, pop

from the stack, push in the string

on the stack, and go to state

. In the initial configuration, the stack has only the symbol

in it. The PDA accepts by empty stack.

Which one of the following options correctly describes the language accepted by

Diagram for Computer Science and Information Technology question 40

Your answerChoose one option.

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Consider the given C-code and its corresponding assembly code, with a few operands U1–U4 being unknown. Some useful information as well as the semantics of each unique assembly instruction is annotated as inline comments in the code. The memory is byte-addressable.

//C-code ;assembly-code (; indicates comments)

;r1-r5 are 32-bit integer registers

;initialize r1=0, r2=10

;initialize r3, r4 with base address of a, b

int a[10], b[10], i; L01: jeq r1, r2, end ;if(r1==r2) goto end

// int is 32-bit L02: lw r5, 0(r4) ;r5 <- Memory[r4+0]

for (i=0; i<10; i++) L03: shl r5, r5, U1 ;r5 <- r5 << U1

a[i] = b[i] * 8; L04: sw r5, 0(r3) ;Memory[r3+0] <- r5

L05: add r3, r3, U2 ;r3 <- r3+U2

L06: add r4, r4, U3

L07: add r1, r1, 1

L08: jmp U4 ;goto U4

L09: end

Which one of the following options is a CORRECT replacement for operands in the position (U1, U2, U3, U4) in the above assembly code?

Your answerChoose one option.

(8, 4, 1, L02)

(3, 4, 4, L01)

(8, 1, 1, L02)

(3, 1, 1, L01)

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A 4 kilobyte (KB) byte-addressable memory is realized using four 1 KB memory blocks. Two input address lines (IA4 and IA3) are connected to the chip select (CS) port of these memory blocks through a decoder as shown in the figure. The remaining ten input address lines from IA11–IA0 are connected to the address port of these blocks. The chip select (CS) is active high.

The input memory address (IA11–IA0), in decimal, for the starting locations (Addr=0) of each block (indicated as X1, X2, X3, X4 in the figure are among the options given below. Which one of the following options is CORRECT?

Diagram for Computer Science and Information Technology question 42

Your answerChoose one option.

(0, 1, 2, 3)

(0, 1024, 2048, 3072)

(0, 8, 16, 24)

(0, 0, 0, 0)

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2023 · Paper 1

Question 40

Question 41

Question 42