MOLINA FINAL EXAM

The symbol for the current location counter is

$

Example 2 1:.data 2:varX DWORD 9,8,7,6,5,4,3,2,1,0 3:varY DWORD (LENGTHOF varX) DUP(0) 4:.code 5:mov esi,OFFSET varY + (SIZEOF varX) - 4 6:mov edi,4 7:mov ecx,LENGTHOF varX - 1 8:L1:mov eax,varX[edi] 9:mov [esi],eax 10:add edi,4 11:sub esi,4 12:loop L1 Refer to Example 2. If line 9 were changed to the following, what would be the final values at locations varY, varY+4, and varY+8? 9: mov [esi-4],eax

0, 1, 2

Form the 8-bit two's complement of each binary integer: 11110001

00001111

Translate the following decimal number to binary: 34

00100010

Translate the following signed decimal number to binary: -78

10110010

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) What is the final hexadecimal value of AL when this code executes? mov ebx,OFFSET byte1 mov al,[ebx+3]

14h

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) What is the hexadecimal value of AX when this code executes? mov esi,OFFSET word1 add esi,4 mov ax,[esi]

2

What is the value of the expression.(TYPE word1)?

2

Which flag is set when an unsigned value is too large to fit into a destination operand?

Carry

A signed integer stores the sign in the least significant bit (LSB).

False

Adding 7Fh and 05h in an 8-bit register sets the Overflow flag.

False

If an integer's sign bit is 1, the integer is positive.

False

The following is a valid identifier: AB62-$T

False

Which instruction moves the lower 16 bits of dword1 into the BX register (hint: use PTR).

mov bx, WORD PTR dword1

The two's complement of an integer is formed by doing which of the following?

reversing (inverting) the bits and adding 1

Which directive identifies the part of a program containing instructions?

.CODE

Example 2 1:.data 2:varX DWORD 9,8,7,6,5,4,3,2,1,0 3:varY DWORD (LENGTHOF varX) DUP(0) 4:.code 5:mov esi,OFFSET varY + (SIZEOF varX) - 4 6:mov edi,4 7:mov ecx,LENGTHOF varX - 1 8:L1:mov eax,varX[edi] 9:mov [esi],eax 10:add edi,4 11:sub esi,4 12:loop L1 Refer to Example 2. After the loop executes, what will be the values at locations varY, varY+4, and varY+8?

0, 0, 1

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) What is the final hexadecimal value of EAX when this code executes? mov edx,8 mov eax,dword1[edx]

00000030h

Which of the following binary values is equivalent to hexadecimal 4A2B?

0100 1010 0010 1011

Add the following binary integers: 00101101 and 00111011:

01101000

Which of the following binary values is equivalent to hexadecimal 7CBE? a. 0111 1101 1011 1110 b. 0111 1011 1011 1100 c. 0111 1100 1100 1110 d. 0111 1100 1011 1110

0111 1100 1011 1110

What will be the hexadecimal value of AL after these instructions execute? mov al,0CFh and al,2Bh

0Bh

Which of the following code sequences assigns the value 10h to EBX? (The following question may have more than one correct answer. Mark all correct)

1 and 2 above

Which of the following code sequences assigns the value 10h to EBX? There may be multiple answers.

1 and 4

Translate the following decimal number to hexadecimal: 258

102

Which of the following is the binary translation of signed decimal -33 ? a. 11011111 b. 10101011 c. 11001100 d. 11100011

11011111

In the following data definition, assume that List2 begins at offset 2000h. What is the offset of the third value (5)? List2 WORD 3,4,5,6,7

2004h

Which list contains the correct hexadecimal translation (in order) of the following unsigned decimal integers? 33, 95, 257

21, 5F, 101

What is the value of the expression (LENGTHOF word1)?

3

What is the result of ax after the following: .data val1 WORD 4000h val2 WORD 5000h val3 WORD 3000h .code main PROC mov ax, val1 add al, 20h sub ah, 10h

3020h

What is the value of the expression (TYPE dword1)?

4

Convert the following string to a sequence of hexadecimal ASCII codes: "BW654" knowing that "A" is 41h and 1 is 31h. Use comas to separate your answer.

42h, 57h, 36h, 35h, 34h

What will be the value of EAX when the following sequence of instructions has executed? Push 5 push 10 pop ebx pop eax

5

What is the value of the expression (SIZEOF word1)?

6

In the following instruction sequence, show the changed values of AL where indicated, in hexadecimal: mov al,9Ch not al

63h

Which format is used to store Little Endian representation for the following 12345678h ? from low to high memory left to right?

78563412

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) What is the final hexadecimal value of AX when this code executes? mov ebx,OFFSET dword1 sub ebx,2 mov ax,[ebx]

9000h

What will be the hexadecimal value of AL after these instructions execute? mov al,94h xor al,37h

A3h

Within the CPU, all calculations and logic operations take place inside the ___________ .

ALU

Given the following array definition, which letter choice contains a valid constant declaration named ArrayCount that automatically calculates the number of elements in the array? newArray DWORD 10,20,30,40,50

ArrayCount = ($-newArray) / 4

What will be the hexadecimal value of AL after these instructions execute? mov al,3Ch or al,82h

BEh

Which answer choice shows the correct values of the Carry, Zero, and Sign flags after the following instructions execute? mov al,00110011b test al,2

CF = 0, ZF = 0, SF = 0

What is the name of the lowest 8 bits of the EDX register?

DL

Which register is known as a loop counter?

ECX

What will be the final value in EDX after this code executes? mov edx,1 mov eax,7FFFh cmp eax,0FFFF8000h jl L2 mov edx,0 L2:

EDX = 0

Which two 32-bit registers are known as extended index registers?

ESI, EDI

Use the following data for the following question: word1 WORD 1000h,2000h,3000h,4000h,5000h dword1 DWORD 10000h,20000h,30000h,40000h What is the final value of AX after this code has executed? mov esi,OFFSET word1 mov ecx,5 mov eax,100h L1:add ax,[esi] add ax,16 add esi,TYPE word1 Loop L1

F150h

A quadword is 4 bytes.

False

The AND and OR always clear the Sign and Overflow flags.

False

The AND and TEST perform exactly the same operations.

False

The DS register can be the destination operand of a MOV instruction.

False

The ESP register always points to the next available position (NAP) where a new value will be pushed on the stack

False

The PUSH instruction copies a value from the stack to an operand before decrementing the stack pointer

False

The RET instruction pops the value pointed to by EBP off the stack into the instruction pointer..

False

The TEST instruction always alters the destination operand.

False

The XOR means as long as one value is 1 the resulting value is also 1.

False

The expression X ˅ Y is only true when X and Y are both true.

False

The following C++ expression cannot be written in assembly language code. X = (Y + 4) * 3;

False

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) The following instructions implement the following expresion dArray[0] = dArray[1] + dArray[2] in assembly language. mov eax, [dArray+4] add eax, [dArray+4] mov dArray, eax

False

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) The following instructions implement the following expresion eax = -dword1 + (edx - ecx) + 1 in assembly language. sub edx, ecx mov eax, dword1 neg eax ; eax = -dword1 add eax, edx inc edx

False

Using the following data declarations, specify if the following instructions code is a proper code with a loop that copied the string from the source to target. source BYTE "String to be copied", 0 target BYTE SIZEOF source DUP(0), 0 mov edi, 0 mov ecx, SIZEOF source L1: mov al, source[edi] mov target [edi], al inc edi loop

False

label word 10, 20, 30, 40, 50 mov ax, label + 4 puts 50 into ax.

False

Which of the following are true about the PUSH instruction?

It decrements the stack pointer (by 2 or 4) and copies the operand into the stack at the location pointed to by the stack pointer.

Which instruction loads the low byte of the EFLAGS register into AH?

LAHF

Which of the following defines a text macro named MESSAGE that contains this string data? "I'm good at this!",0

MESSAGE TEXTEQU <"I'm good at this!",0>

A doubleword (on x86 systems) is 32 bits.

True

A link library contains procedures that have already been assembled into object code.

True

A signed byte can be equal to +127.

True

A word (on x86 systems) is 16 bits.

True

Adding 0FFh and 05h in an 8-bit register sets the Overflow flag.

True

Adding 5 to 0FBh in an 8-bit register sets the Zero flag.

True

For any two integers n and m, ((n XOR m) XOR m) produces n.

True

In a stack, the first value pushed on a stack is the last one to be removed.

True

The ES register can the source operand of a MOV instruction.

True

The INC instruction does not affect the Carry flag.

True

The MOV instruction does not permit an immediate value to be moved to a segment register.

True

The MOVSX instruction sign-extends an integer into a larger operand.

True

The NOT instruction inverts all of the bits in an operand.

True

The expression X ˄ Y is true only when X and Y are both true.

True

The following instructions will set the Carry flag: mov al,0FEh sub al,2

True

The following instructions will set the Sign flag: mov al,0FEh sub al,2

True

The listing file contains a list of program symbols.

True

The three most basic operators in Boolean algebra are AND, OR, and NOT.

True

Three hexadecimal digits can be used to represent 12 binary bits.

True

Use the following data definitions until notified otherwise: byte1 BYTE 0FFh,1,2 byte2 BYTE 14h word1 WORD 0FFFFh,1,2 word2 WORD 3 word3 SWORD 7FFFh,8000h word4 SWORD 9000h dword1 DWORD 10h,20h,30h,40h dArray DWORD 10 DUP(?) The following statements move the content of word1 to word2: mov ax, word1;(any general-purpose 16 bit register may be used) mov word2, ax

True

What is the value of the boolean expression X ˅ (Y ˄ Z), when X=true, Y=false, and Z=false?

True

val3 DWORD 20 DUP (?) means there are 80 bytes of data that will be placed beginning at val3 at runtime.

True

Is the expression X ˅ (Y ˄ Z) equivalent to (X ˅ Y) ˄ (X ˅ Z) for all possible inputs of X, Y, and Z?

Yes

The byte-ordering scheme used by computers to store large integers in memory with the high-order byte at the lowest address is called:

big endian

High-speed memory that reduces the frequency of access by the CPU to conventional memory is called

cache memory

Which of the following CALL instructions writes the contents of EAX to standard output as a signed decimal integer?

call WriteInt

The four parts of a CPU are:

clock, registers, control unit, arithmetic logic unit

The three types of buses connected to the CPU are:

data, address, control

During which phase of the instruction execution cycle is the program counter incremented?

fetch

List the three primary steps of the instruction execution cycle, in sequential order:

fetch, decode, execute

The basic parts of an instruction, in order from left to right, are:

label, mnemonic, operand(s), comment

Select the answer choice that best implements the following expression. Do not permit dword1, ECX, or EDX to be modified: eax = -dword1 + (edx - ecx) + 1

mov eax,dword1 neg eax mov ebx,edx sub ebx,ecx add eax,ebx inc eax

Which instruction moves the 32-bit address of word1 into the ESI register (assume 32-bit Protected mode).

mov esi, OFFSET word1

Select a data definition statement that creates an array of 500 signed doublewords named myList and initializes each array element to the value ?1.

myList SDWORD 500 DUP (-1)

If you wanted to find out whether an integer contained an even number of 1 bits, which status flag would be useful?

parity