Description
Purpose
Gain familiarity with the MIPS instruction set by assembling, simulating, and analyzing a sample MIPS program.
Tasks
-
-
Install MIPSASM 2.15 (MIPS Assembler and Simulator) and MARS (MIPS Assembler and Runtime Simulator).
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Assemble the MIPS assembly code below (the asm file is provided) into a file called “mipstest.asm”. For each MIPS instruction, compare the machine code generated by two different assemblers.
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Single step through the instructions and verify contents of the relevant register(s). Record the execution results in the test log table on the next page (a Word version is provided) and note the memory value at address 80 (0x50) and 84 (0x54) after 19 instructions.
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Complete a lab report that contains the source code, the test log, screen captures of the appropriate execution windows, a discussion section, a collaboration section, and a conclusion section. In the discussion section, discuss your observations in the test log and try to explain them with the help of the MIPS Reference Data Card.
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mipstest.asm
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Test the following MIPS instructions.
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add, sub, and, or, slt, addi, lw, sw, beq, j
|
# |
Assembly |
$0, 5 |
Description |
= |
5 |
Address |
Machine |
|
|
main: |
addi $2, |
# initialize $2 |
3000 |
20020005 |
||||
|
addi $3, |
$0, 12 |
# initialize $3 |
= |
12 |
3004 |
2003000c |
||
|
addi $7, |
$3, -9 |
# initialize $7 |
= |
3 |
3008 |
2067fff7 |
||
|
or |
$4, |
$7, $2 |
# $4 <= 3 or 5 = 7 |
300c |
00e22025 |
|||
|
and |
$5, |
$3, $4 |
# $5 <= 12 and 7 = 4 |
3010 |
00642824 |
|||
|
add |
$5, |
$5, $4 |
#$5=4+7=11 |
3014 |
00a42820 |
|||
|
beq |
$5, |
$7, end |
# shouldn’t be taken |
3018 |
10a7000a |
|||
|
slt |
$4, |
$3, $4 |
#$4=12<7= |
0 |
301c |
0064202a |
||
|
beq |
$4, |
$0, around |
# should be taken |
3020 |
10800001 |
|||
|
addi $5, |
$0, 0 |
# shouldn’t execute |
3024 |
20050000 |
||||
|
around: slt |
$4, |
$7, $2 |
#$4=3<5=1 |
12 |
3028 |
00e2202a |
||
|
add |
$7, |
$4, $5 |
#$7=1+11= |
302c |
00853820 |
|||
|
sub |
$7, |
$7, $2 |
#$7=12-5= |
7 |
3030 |
00e23822 |
||
|
sw |
$7, |
68($3) |
#[80]=7 |
3034 |
ac670044 |
|||
|
lw |
$2, |
80($0) |
#$2=[80]=7 |
3038 |
8c020050 |
|||
|
j |
end |
$0, 1 |
# should be taken |
303c |
08000c11 |
|||
|
end: |
addi $2, |
# shouldn’t execute |
3040 |
20020001 |
||||
|
sw |
$2, |
84($0) |
# write adr 84 = 7 |
3044 |
ac020054 |
|||
|
j |
main |
# go back to beginning |
3048 |
08000c00 |
||||
CMPE200 – Laboratory Assignment 2 Test Log
Configure the data segment on MARS to start at address 0 (Settings – Memory Configuration).
Assemble the given MIPS instructions on both MARS and MIPSASM. Single step through the given
MIPS instructions. Observe and record the following values in the test log table:
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the actual machine code for both MARS and MIPSASM
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contents of the program counter (PC) and the relevant registers for MARS
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contents of memory at location 80 (0x50) and 84 (0x54) for MARS.
|
Adr |
Machine Code |
Machine Code |
PC |
Registers |
Memory Content |
|||||||
|
for MARS |
for MIPSASM |
$v0 |
$v1 |
$a0 |
$a1 |
$a3 |
[80] |
[84] |
||||
|
3000 |
||||||||||||
|
3004 |
||||||||||||
|
3008 |
||||||||||||
|
300c |
||||||||||||
|
3010 |
||||||||||||
|
3014 |
||||||||||||
|
3018 |
||||||||||||
|
301c |
||||||||||||
|
3020 |
||||||||||||
|
3024 |
||||||||||||
|
3028 |
||||||||||||
|
302c |
||||||||||||
|
3030 |
||||||||||||
|
3034 |
||||||||||||
|
3038 |
||||||||||||
|
303c |
||||||||||||
|
3040 |
||||||||||||
|
3044 |
||||||||||||
|
3048 |
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