CMPE 200 – Assignment 3 MIPS Instruction Set Architecture & Programming (2)

Description

Purpose

Gain familiarity with MIPS ISA control structures and the $hi and $lo registers.

Tasks

1. Write a MIPS assembly program to perform the arithmetic computation shown in the following C++ pseudo code. Note that the C++ pseudo code has several variables (a, b, c, x, and y). Use the following registers to store the values of these variables:

$a0  a

$a1  b

$s0  c

$s1  x

$s2  y

• Variables initialization

1. a = 0x8000; #MIPS instruction: ori $a0, $0, 0x8000

• 2. b = 0x00A9;

  3. c = 1974;

• Arithmetic computation

• 4. x = a * a;

  5. store the value of x to memory location at address 0x20;

• 4. y = x * b;

  5. store the value of y to memory location at address 0x24;

  6. y = y >> 16;

• 4. c = (c + y / c) / 2;

  5. store the value of c to memory location at address 0x2C;

• While loop

• 11. while(c >= 1665){

  12. c = (c + y / c) / 2;

• 11. }

  12. c = c << 8;

  13. store the value of c to memory location at 0x30;

Requirements: Use no more than 28 real MIPS instructions.

2. Assemble your MIPS assembly code and single-step execute through all instructions. After the execution of each instruction, verify the contents of the relevant registers. Record the execution results using the test log table on page 3 of the assignment, and note the value at the following memory addresses when the program execution has completed:

2. • 0x20 – 0x23;

2. • 0x24 – 0x27;

0x28 – 0x2b;

2. • 0x2c – 0x2f;

2. • 0x30 – 0x33;

2. Write a MIPS assembly program to calculate the factorial of a given integer n. The factorial of n is defined as

n! = n*(n-1)*…*1

Note that 0! = 1.

Algorithm for computing factorial:

1. INPUT n = 5; //given number n

2. f = 1;

3. while (n > 1)

{

f = f * n; n = n – 1;

}

4. OUTPUT f; //factorial f = n!

Requirements:

1.	Input number n = 5, to be stored in memory location at address 0x00.
2.	Register assignment: $a0  n; $s0  n!

1. 3. You must use the algorithm shown above.

   4. The assembly program shall contain no more than 11 real MIPS instructions.

   5. The factorial of 5 must be written to the memory location at address 0x10.

4. Assemble the MIPS assembly code, single-step execute through each instruction and verify the contents of the relevant registers after each instruction’s execution. Record the execution results using the test log table on page 4, and indicate the value at the following memory addresses when the entire program is executed:

4. • 0x00 – 0x03;

4. • 0x10 – 0x13;

4. Write your lab report. It should include the source code, the recorded test results (typed test logs), screen captures of the appropriate execution windows generated by the assembler (e.g., MARS), a collaboration section, a discussion section, and a conclusion section.

		CMPE200 Assignment 3 Task 1 Test Log
			Algorithm 1
Programmer’s Name: _____________________________
Date:___________________________
	Adr	MIPS Instruction	Machine			Registers
				$a0	$a1	$s0	$s1	$s2
			Code

3000

3004

3008

300c

3010

3014

3018

301c

3020

3024

3028

302c

3030

3034

3038

303c

3040

3044

3048

304c

3050

3054

3058

305C

3060

3064

3068

306C

Memory contents

CMPE200 Assignment 3 Task 2 Test Log

Algorithm 2

Programmer’s Name: __________________________________

Date:___________________________

Adr	MIPS Instruction	Machine		Registers			Memory Content
			$a0	$s0	$t0	$t1	Word @ 0x00	Word @ 0x10
		Code
3000
3004
3008
300c
3010
3014
3018
301c
3020
3024
3028

2