Im trying to make a program that output time like this: 00:00:00 all the way to 12:59:59
here is my code it only loops around the second and nothing else is outputs it output from 0:0:0 to 0:0:59
what am I doing wrong and how can i get the output in format ##:##:##
.data
str2: .asciiz ":"
space: .asciiz "\n"
.text
main:
li $t0,1
hour:
bgt $t0,12,exit
minutes:
bgt $t1,59,hour
seconds:
bgt $t2,59,minutes
li $v0, 1
move $a0, $t0
syscall
li $v0,4
la $a0,str2 #load and print string
syscall
li $v0, 1
move $a0, $t1
syscall
li $v0,4
la $a0,str2 #load and print string
syscall
li $v0, 1
move $a0, $t2
syscall
addi $v0, $zero, 4
la $a0, space
syscall
addi $t2,$t2,1
j seconds
addi $t1,$t1,1
j minutes
addi $t0,$t0,1
j hour
exit:
minutes:
bgt $t1,59,hour ; 1
seconds:
bgt $t2,59,minutes ; 2
li $v0, 1 ; 3
:
addi $t2,$t2,1
j seconds
When $t2 eventually gets to 60, that code segment you have there is going to be an infinite loop.
Nowhere in the code are you actually setting $t2(secs) back to zero and incrementing $t1(mins) so, once $t2 hits 60 and you jump to seconds, here's the execution path: 2, 1, 2, 1, 2, ..., with no chance of advancing to 3 again.
As to how to fix it, don't just jump back to minutes when $t2 overflows, you have to set $t2 back to zero and increment $t1. Then you need to check $t1 for overflow and so on.
Since it's probably classwork, I'll offer pseudo-code (of an assembler variety) only, but possibly the best way to structure your code would be:
start:
$t0 = 0
$t1 = 0
$t2 = -1
loop:
$t2 = $t2 + 1
if $t2 < 60 goto skipmin
$t2 = 0 ; special when secs -> 60
$t1 = $t1 + 1
skipmin:
if $t1 < 60 goto skiphour
$t1 = 0 ; special when mins -> 60
$t0 = $t0 + 1
if $t0 == 24 goto end ; stop at 24:00:00
skiphour:
display $t0:$t1:$t2
goto loop
end:
stop program
As to how to display values with leading zeroes, again with pseudo-code (for just the seconds value, you'll have to expand it to handle minutes and hours):
if $t2 > 9 goto nozerosec
syscall 4 with $a0 pointing at "0"
nozerosec:
syscall 1 with $a0 loaded from $t2
This simply works by checking the value you're going to output and, if it's less than 10, outputting a leading zero first.
This is assuming (as it seems to be) that syscall 1 is for outputting a value in $a0 and syscall 4 is for outputting a string pointed to by $a0.
And, for extra credits, you can make the padded output a separate function to be called rather than repeating yourself in the main program.