EE 3755 Homework 5  Due: TBA (After covering MIPS Note1 and Note2)

Estimated time to solve:

Prob.1     40 mins.

Prob.2      30 mins.

Prob.3      20 mins.

Prob.4      10 mins.

Prob.5      40 mins.

Prob.6     30 mins.

Prob.7     10 mins.

Total:     180 mins.

Problem 1: Answer the questions without looking anything.(this is practice, so do not use the simulator program although you may check the correctness of your answer)

LOOP:

beq r0,r0, LOOP

(For the problem 1.1)

1.1)Write Machine code for the above 3 instructions.

Hint :

opcode for add is 0 and func field is 0x20.

opcode for addi is 8 and think about rt and rs fields.

opcode for beq is 4

What will be the offset value for LOOP.

START:

0x400000    J LINE1

nop

LINE1       beq r0,r0,LINE2

LINE2       nop

(For the problem1.2)

1.2)Write Machine code for the above 5 instructions.

Hint :

opcode for j is 2 .

What will be the offset value for LINE1 and LINE2.

0x400000    bne r1, r2,2

0x40000c    bne r1,r2,-2

Problem 2: Briefly explain about three instruction formats for MIPS.

(Less than 20lines.

a)      How big is each field at each format?

b)      Field position.

Problem 3. write the  register values after executing following instructions.

Loop:

 0x1000 Addi r1, r0, 3; R1= Addi r2, r0, 5; R1= R2= Sub  r3, r1, r2; R1= R2= R3= Sub  r4, r1, r2; R1= R2= R3= R4= R31= Beq  r3, r0, loop; R31= ori    r1, r2, 20; R1= R2= R3= R31= Addi  r4, r0, 0x2000; R1= R2= R3= R4= R31= jalr r4; R1= R2= R3= R4= R31=

Problem 4: True(right) or False(wrong) instruction .

T      F

4-2)  subi \$t0,\$t1,0x1234

4-3)  jr    \$0x123456

4-4)  j     0x123456789

Problem 5:  Briefly explain about the register usage for procedure call.

Problem6:  What is the MIPS assembly code for the following C code?

//c..

# Reg Usage: j, \$8;  sum, \$9;

for(j = 0, j < 4;++j){

sum = sum + j;

}

Problem 7: Write real code for the following pseudo code.

7.1)li \$2, 0x12345678

7.2)mul \$2, \$3, \$4

7.3)nop

7.4)move \$1, \$2