.data
.word 5
.word 4
.word 3
.word 2
.word 1
.text
.globl main
addi $t5, $zero, 0x10010000 #base address - 0x10010000
main:
Loop:
addi $t0, $t0, 0
bge $t0, 5, Exit
sll $t1,$t1,2
add $t2, $t5, $t1
lw $t3, 0($t2)
sll $t3,$t3,1
sw $s0, 0($t3)
addi $t0,$t0,1
j Loop
Exit:
The error I discovered was in sw $s0, 0($t3). The exception is the following: store address not aligned on word boundary 0x0000000a. Based on this error, it looks like there is no word alignment. What is the best way to fix the error?
Your feedback (or constructive criticism) is greatly appreciated.
Related
I am not sure where I am messing up, but I am using the MARS emulator for MIPS and am running into an error at my
lw $s6, 0($s7) #s6 now holds c[i] line.
here is my error:
Error in C:\Programming\mips1.asm line 14: Runtime exception at 0x00400020: address out of range 0x20000000
Go: execution terminated with errors.
.text
.globl main
main:
add $s0, $zero, $zero
lui $s3, 0x2000
addi $s5, $zero, 100
addi $sp, $sp, -8
Loop:
slt $t2, $s0, $s5
beq $zero, $t2, Exit
sll $s7, $s0, 2
add $s7, $s7, $s3 #s7 is now the address of c[i]
lw $s6, 0($s7) #s6 now holds c[i]
slt $t3, $s0, $s1 #set t3 if i is less than a
bne $zero, $t3, Else
sw $s2, 0($s7) #stores b into c[i]
add $s0, $s0, 1
j Loop
Else: add $s2, $zero, $s6
add $s0, $s0, 1
j Loop
Exit: addi $sp, $sp, 8
li $v0, 10
syscall
I solved it, turns out I needed an address that was lower in order for it to be a part of the heap. MARS heap starts at 0x10040000 and moves up.
I changed 0x2000 to 0x1005 and it worked in MARS
I am working on my first project in mips, trying to print the sum of all the positive numbers in an array. I am now testing my code with QtSpim and have been getting an error saying I am using the main label twice even though there is only one occurrence. There is also no output, regardless of whether or not I include the main label. Here's the code:
.data
A: .word -89, 19, 91, -23, -31, -96, 3, 67, 17, 13, -43, -74
.text
main:
addi $s0, $zero, 0 #set $s0 for sum of positive nums to 0
la $s1, A #set $s1 to array address
addi $t0, $s1, 48 #set $t0 to exit point
while:
beq $s1, $t0, end
lw $t1, A($s1)
slt $t2, $t1, $zero
bne $t2, $zero, else #skips addition step if A at $s1 is negative
add $s0, $s0, $t1
else:
addi $s1, $s1, 4
j while
end:
li $v0, 1
move $a0, $s0
syscall
li $v0, 10
syscall
Sorry if this is bad formatting for mips, I have only ever worked with Java and C++.
there's an error on this line
lw $t1, A($s1)
What I believe you want is
lw $t1, 0($s1)
A positive integer must be in the offset of the lw instruction.
The main label error seems like a rabbit hole as you see no label was used more than once.
So I am using QtSpim to run my mips program for school. I basically made a working program, but now i keep getting an exception error. I've tried cutting down my code, so here is where the error starts now.
.text
.globl main
main:
.data
message1: .asciiz "The maximum is "
message2: .asciiz "The summation is "
myArray: .space 32
.text
addi $s0, $zero, 11
addi $s1, $zero, 12
addi $s2, $zero, -10
addi $s3, $zero, 13
addi $s4, $zero, 9
#addi $s5, $zero, 12 not needed
addi $s5, $zero, 14
addi $s6, $zero, 15
addi $s7, $zero, -20
addi $t0, $zero, 0
sw $s0, myArray($t0)
addi $t0, $t0, 4
li $v0,10
syscall
The error is sw $s0, myArray($t0)
You likely need to make sure myArray is aligned to a 32-bit boundary. I suggest trying a .align directive before its declaration.
.data
stack: .word 3, 2
.text
.globl main
main:
la $s1, stack #assign stack start memory to $s1
addi $t3, $t3, 0 #clear $t3
addi $t3, $t3, 4 #assign 4 to $t3
add $s1, $s1, $t3 #second member of stack
lw $t1, 0($s1) #d2
addi $t3, $t3, -4 #move $t3 forward
add $s1, $s1, $t3 #first member of stack
lw $t0, 0($s1) #d1
add $t0, $t0, $t1 #d1 = d1 +d2
sw $t0, 0($s1) #store new d1 at d1's location
I'm trying to create a mips program, which gets last-1 and last member of the stack, and add them, and store it. I don't care about addi $t3, $t3, 4 or stack: .word 3, 2 it's just for test.
However, when I run this at qtspim I got an error message "attempt to execute non-instruction at 0x0040004c" please enlighten me as to what the problem is.
You need to end your program with a jr $ra, otherwise the processor will just keep executing whatever random instructions that happen to come after the sw $t0, 0($s1).
For a homework assignment in school, I need to use a MMIO LED display where each led is exactly 2 bits stored within a byte. For the assignment I need to "move" these LEDs up, down, left, and right. I also need to set the color (I will be using 0x40 for this). Here's my issue:
When I click the "right" arrow to move the LED over 1 column, it remains in the current column when it should be returning to black (0x00). If I click right 4 times (moving over exactly 1 byte), I get another lit LED, leaving the original one there.
Here is my MIPS code:
getLedPattern:
move $t2, $s2
andi $t1, $t2, 0x3 #remainder of x / 4 is in $t0
sll $t0, $t2, 2 #x / 4 is in $t0
beq $t0, 0, case0
beq $t0, 1, case1
beq $t0, 2, case2
case3:
andi $a0, 0xFFFFFFFC
#insert $a1 into bits 0 and 1 of $a0 into $v0
or $v0, $a0, $a1
jr $ra
case2:
andi $a0, 0xFFFFFCFF
#insert $a1 into bits 2 and 3 of $a0 into $v0
#srl $a1, $a1, 2
or $v0, $a0, $a1
jr $ra
case1:
andi $a0, 0xFFFCFFFF
#insert $a1 into bits 4 and 5 of $a0 into $v0
#srl $a1, $a1, 4
or $v0, $a0, $a1
jr $ra
case0:
andi $a0, 0xFCFFFFFF
#insert $a1 into bits 6 and 7 of $a0 into $v0
#srl $a1, $a1, 6
or $v0, $a0, $a1
jr $ra
setLED:
addi $sp, $sp, -20
sw $ra, 0($sp)
sw $t0, 4($sp)
sw $t1, 8($sp)
sw $t2, 12($sp)
sw $t3, 16($sp)
move $t5, $a0
sll $t6, $a1, 5 # y*32
srl $t2, $a2, 2 # x/4
add $t5, $t5, $t6
add $t5, $t5, $t2
lb $a0, 0($t5)
move $a1, $a3
jal getLedPattern
sb $v0, 0($t5)
move $s3, $t5
lw $ra, 0($sp)
lw $t0, 4($sp)
lw $t1, 8($sp)
lw $t2, 12($sp)
lw $t3, 16($sp)
addi $sp, $sp, 20
jr $ra
The logic is that it starts out at at memory location 0xFFFFOOO8 (top left LED), moves down one row (+32 bytes) and over x columns (plus x*bits). However, I can't seem to unset the current LED and move it over one. Any help would be appreciated. I believe that my or in getLedPattern: is wrong, but not 100% sure.
Hopefully, getting this correct I will be able to get this correct in a general sense (no LED display).
I guess that your constants for clearing bits are wrong.
try the following instead:
0xfffffffc // or ~0x03
0xfffffff3 // or ~0x0C
0xffffffcf // or ~0x30
0xffffff3f // or ~0xC0
There are other oddity in your code:
s2 is used, but never set
s3 is set, but never used
case1 and case2 will never be reached because $t0 can hold nor 1 neither 2