Chapter 9 & 10

Question 1

MOVSB, MOVSB, and MOVSD

Answer 1

Move the string BYTE, “”WORD, “”DWORD

Copies data from the memory location pointed to by ESI to the memory location pointed to by EDI

Question 2

Direction Flag

Answer 2

Controls the inc or dec of ESI and EDI

DF = 0 - forward/increment
DF = 1 - backward/decrement

Question 3

CLD

Answer 3

Clear Direction Flag

Question 4

STD

Answer 4

Set Direction Flag

Question 5

Repeat Prefix

Answer 5

REP - inserted before MOVSB, MOVSW, etc.

ECX controls num reps

REPE(REPZ)
REPNE(REPNZ)

Question 6

CMPSB, CMPSW, and CMPSD

Answer 6

Compare string byte, “”WORD, “”DWORD

Compares a memory operand pointed to by ESI to a memory operand pointed to by EDI

Question 7

SCASB, SCASW, and SCASD

Answer 7

Scan string byte, WORD, DWORD

Compares a value in AL/AX/EAX to a byte, word, or DWORD addressed by EDI

Question 8

LODSB, LODSW, LODSD

Answer 8

Load string byte,…

Loads a byte or word from memory at ESI into AL/AX/EAX respectively

Question 9

Str_compare Procedure

Answer 9

Compares string1 and string2

Question 10

Str_length Procedure

Answer 10

Calculates the length of a null-terminated string and returns the length in the EAX register

Question 11

Str_copy Procedure

Answer 11

Copies a null-terminated string from a source location to a target location

Question 12

Str_trim

Answer 12

Removes all occurrences of a selected trailing character from a null terminated string

Question 13

Str_ucase Procedure

Answer 13

Converts a string to all uppercase characters

Question 14

Base-Index Operand

Answer 14

Adds the values of two registers (called base and index), producing an effective address

Question 15

Base-Index-Displacement Operand

Answer 15

Adds the base and index registers to a constant, producing an effective address

Question 16

Structure

Answer 16

Template/pattern given to a logically related group of variables

Syntax:
Name STRUCT
Field declarations
Name ENDS

Question 17

Union

Answer 17

Same as structure except all fields begin at the same offset

Question 18

Macro

Answer 18

Named block of assembly statements

During the assembler preprocessing step, each macro call is expanded into a copy of the macro

Question 19

Default Argument Initializer

Answer 19

Automatically assigns a value to a parameter when a macro argument is left blank

Ex:
mWriteLn MACRO text:=
…
ENDM

Question 20

IFIDN and IFIDNI

Answer 20

Both compare two symbols and return true if they are equal

IFIDN is case sensitive

IFIDNI is case insensitive

Question 21

&

Answer 21

Substitution Operator

• resolves ambiguous references to parameter names within a macro

Question 22

%

Answer 22

Expansion Operator

• expands text macros or converts constant expressions into their text representations

Question 23

<>

Answer 23

Literal-text Operator

• groups one or more characters and symbols into a single text literal

Question 24

!

Answer 24

Literal-character Operator

• forces the preprocessor to treat a predefined operator as an ordinary character

Question 25

WHILE Directive

Answer 25

Repeats a statement block as long as a particular constant expression is true

Syntax:
WHILE constExpr
statements
ENDM

Question 26

REPEAT Directive

Answer 26

Repeats a statement block a fixed number of times

Syntax:
REPEAT constExpr
Statements
ENDM

Question 27

FOR Directive

Answer 27

Repeats a statement block by iterating over a comma-delimited list of symbols

• each symbol in the list causes one iteration

Syntax:
FOR parameter
…
ENDM