1. MIPS Assembly Language Programming
CDA 3101 Fall 2010
Discussion Session 07
MIPS Assembly Language Programming 1 1

2. Instruction Register add $t0, $t1, $t2 ## RF[Rd] =RF[Rs] +RF[Rt]
Register – Format (add Rd, Rs, Rt)‏
Op-code Rs Rt Rd
Shamt
Function-code 6 5 5 5 5 6
add $t0, $t1, $t ## RF[Rd] =RF[Rs] +RF[Rt] 2 2 2

3. Instruction Register addi $t0, $t1, 100 ## RF[Rt] =RF[Rs] + se Imm
Immediate – Format (addi Rt, Rs, Imm)‏
Op-code Rs Rt
Immediate 6 5 5 16
2’s Complement ?
addi $t0, $t1, ## RF[Rt] =RF[Rs] + se Imm
se Imm = {16 {immediate[15]}, immediate}
beq Rs, Rt, Label ##if(RF[Rs] == Rf[Rt]) PC = PC +4 + BranchAddr*
*BranchAddr = {14{immediate[15]}, immediate, 2’b0} 3 3 3

4. Instruction Register j Label ## PC = JumpAddr Jump– Format (j addr)‏
Op-code
Address 6 26
j Label ## PC = JumpAddr
JumpAddr = { PC[31:28], address, 2’b0} 4 4 4

5. Problem Assume the address start from 0x00400024, translate the
following MIPS code into the corresponding machine code.
lable1: addi $t0, $0, x
sll $t0, $t0, x
bgez $t0, lable x C
and $s0, $s0, $t x
lable2: bne $s0, $0, lable3 0x
lb $t4, 8($s4) x
sb $t4, -8($s4) x C
lable3: j lable x 5 5 5

6. Problem
[0x ] ;addi $8, $0, 1
[0x ] ;sll $8, $8, 2
[0x c] ;bgez $8 -12 [lable1-0x c - 4]
[0x ] ;and $16, $16, $8
[0x ] ;bne $16, $0, 8 [lable3-0x ]
[0x ] ;lb $12, 8($20)
[0x c] ;sb $12, -8($20)
[0x ] ;j 0x [lable1] 6 6 6