Homework #2 - Due Oct. 7 (Tuesday)

The high-level language program to calculate x^y could be written as

Main Program:
	result := 1
	for counter := 1 to y do
	     result := result * x
	end for

In assembly language this translates to the following program:

#  Mark Fienup <Your name here as a comment> 
 	.data
x:	.word 2
y:	.word 3
result:	.word 0

	.text
	.globl main
main:
	lw	$8, x			# store x in reg. $8
	lw 	$9, y			# store y in reg. $9
	li 	$10, 1			# store result in $10 and initialize it to 1
for:
	li 	$11, 1			# store counter in $11 and initialize it to 1
for_compare:
	bgt	$11, $9, end_for
for_body:
	mul	$10, $10, $8		# mult. result by x
	addi	$11, $11, 1
	j	for_compare
end_for:

	sw	$10, result

	li	$v0, 10		# system code for exit
	syscall

Turn in: Print out of the file containing the program and the resulting PCSpim window after running the program (directions on back).

Entering the Program using Notepad:

1. Start | All Programs | Accessories | Notepad
2. Type in the program in a new file
3. File | Save As
   • Save in: YourAccount on 'Student-CNS Server (Student)' (Z)
   • File name: "hw2.s" (USE DOUBLE-QUOTES AROUND FILE NAME)
4. Print a copy of the program to hand in

Running the Program using PCSpim:

1. Start | All Programs | Programming | PCSpim
2. Maximize the window by clicking on the 2nd icon in the upper right of the window
3. Load the program by File | Open
4. Run the program by Simulator | Go

   • Click "OK" in the Run Parameters window

5. Copy the PCSpim window to the Window's Clipboard using <Alt><Print Screen> keys

Printing the PCSpim window using Word:

1. Start | All Programs | Microsoft Office XP | Microsoft Word
2. Paste in the PCSpim window from the Clipboard by Edit | Paste
3. Change to landscape by File | Page Setup and then click "Lanscape" button
4. Resize the frame containing the PCSpim picture by

   • clicking on the frame

   • drag the lower-right corner to make the picture bigger

5. Print this picture of the PCSpim window to hand in