Objectives:

This exercise aims to demonstrate how Assembly code translates to the circuits, which is what you already learned reading about the IA32 architecture.

Description:

Below is the code that calculates the users age in dog years. Considering that the .data segment starts at the address 0x1000 in main memory, the .code segment start at the address 0x2000 in cache memory, and the value for the age the user gives is 20, write down the changes in variables and registers for each instruction. Assume that when the OFFSET operator in used, only the address of the variable is fetched, NOT the data. The first 4 instructions are given. You can stop after the instruction exit

EXTRA CREDIT (+10 points):

Modify the code in Visual Studio so when the user enters a number for their age below 5, the program prints out a message Wow! That young, yet you know how to use a computer!.

What to submit:

Both, the document file with the program execution and the .asm file for the extra credit.

TITLE Dog years (demo1.asm)

; Description: This program gets the age of the user and calculates their age in dog years (age x 7).

INCLUDE Irvine32.inc

.data

age DWORD ? ; User's age

hi_there BYTE "Hi there, this is John",0 ; Greeting the user

prompt1 BYTE "Can I have your age please?",0 ; Gets age

output BYTE "So, your age in dog years is: ",0 ; Reposts dog age

byebye BYTE "Thanks for passing by, have a great day!",0 ; Bye bye

.code

main PROC

; Greet the user

mov EDX, OFFSET hi_there ; Set up for call to WriteString and greet the user

call WriteString

call Crlf

; Gets the user's age

mov EDX, OFFSET prompt1 ; Asks the user's age

call WriteString

call Crlf

call ReadInt ; Reads the users age. Age in EAX

call Crlf

; Calculate the dog years and stores the dog age

mov EBX, 7

mul EBX

mov age, EAX ; Stores the users dog age. Dog age also in EAX

; Reports the dog years and says bye

mov EDX, OFFSET output

call WriteString

mov EAX, age

call WriteDec

call Crlf

mov EDX, OFFSET byebye

call WriteString

call Crlf

exit ;exit to operating system

main ENDP

END main

Address	Instruction	EIP	EIR	EID	MDR	MAR	EAX	EBX	ECX	EDX	age
0x2000	main PROC	0x2004	main PROC	main PROC	?	?	?	?	?	?	?
0x2004	mov EDX, OFFSET hi_there	0x2008	mov EDX, OFFSET hi_there	mov EDX, OFFSET hi_there	?	0x1004	?	?	?	0x1004	?
0x2008	call WriteString	0x200C	call WriteString	call WriteString	0	0x101A	?	?	?	0x1004	?
0x200C	call Crlf	0x2010	call Crlf	call Crlf	0	0x101A	?	?	?	0x1004	?