Difference between revisions of "CSC231 Addressing Mode Exercises"
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Indicate the addressing used by each of the instructions below. | Indicate the addressing used by each of the instructions below. | ||
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Write a program that changes all the characters of an all-uppercase string to all-lowercase. We assume the string does not contain blank spaces. You can find an ASCII table [http://www.asciitable.com/ here]. | Write a program that changes all the characters of an all-uppercase string to all-lowercase. We assume the string does not contain blank spaces. You can find an ASCII table [http://www.asciitable.com/ here]. | ||
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Write a program that fills an array of 8 bytes with the first 8 powers of 2: 1, 2, 4, 8, 16, etc. | Write a program that fills an array of 8 bytes with the first 8 powers of 2: 1, 2, 4, 8, 16, etc. | ||
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Write a program that fills an array of 16 words with the first 16 fibonacci terms | Write a program that fills an array of 16 words with the first 16 fibonacci terms | ||
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Write a program that fills an array of 10 double-words with the first 10 powers of 2. | Write a program that fills an array of 10 double-words with the first 10 powers of 2. | ||
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Assume Powers is an array of 11 words, and the first word contains a constant. Write the program that stores 1/2 the value of the constant in the 2nd word, 1/4 the value in the 3rd word, 1/8 4th word, 1/16 5th word, etc. | Assume Powers is an array of 11 words, and the first word contains a constant. Write the program that stores 1/2 the value of the constant in the 2nd word, 1/4 the value in the 3rd word, 1/8 4th word, 1/16 5th word, etc. | ||
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The example below copies a string into another string, reversing the order of the string to see if they are palindromes. Rewrite it using a ''based indexed'' addressing mode. | The example below copies a string into another string, reversing the order of the string to see if they are palindromes. Rewrite it using a ''based indexed'' addressing mode. | ||
Revision as of 06:20, 2 October 2014
Contents
Exercises on Addressing Modes
Exercise 1
Indicate the addressing used by each of the instructions below.
;;; ------------------------------------------------------------
;;; Identify possible errors in the instructions below, and
;;; indicate the addressing mode for each one.
;;; ------------------------------------------------------------
section .data
a db 3
b db 0x12345678
c dw 0
x dd 30
array dd 1,2,3,4,5,6,7,8,9,10
section .text
global _start
_start: mov eax, a
mov eax, dword[a] ; is it an error?
mov ebx, array
mov eax, dword[ebx]
mov esi, 0
mov dword[ebx+esi], 0
mov dword[ebx+esi+4], eax
mov edi, b
mov byte[edi], 'Z'
add al, 'z'-'Z'
mov ecx, 10
for: inc ecx
loop for
;;; exit()
mov eax,1
mov ebx,0
int 0x80 ; final system call
Exercise 2
Write a program that changes all the characters of an all-uppercase string to all-lowercase. We assume the string does not contain blank spaces. You can find an ASCII table here.
Exercise 3
Write a program that fills an array of 8 bytes with the first 8 powers of 2: 1, 2, 4, 8, 16, etc.
Exercise 4
Write a program that fills an array of 16 words with the first 16 fibonacci terms
Exercise 5
Write a program that fills an array of 10 double-words with the first 10 powers of 2.
Exercise 6
Assume Powers is an array of 11 words, and the first word contains a constant. Write the program that stores 1/2 the value of the constant in the 2nd word, 1/4 the value in the 3rd word, 1/8 4th word, 1/16 5th word, etc.
Exercise 7
The example below copies a string into another string, reversing the order of the string to see if they are palindromes. Rewrite it using a based indexed addressing mode.
