convert number to ascii in mips?

[coni113]

I'm writing a function write_unsigned_int to convert a number to its ascii to write to a string buffer. So far I can only get it to write to the string buffer backwards. Should I create a new buffer and then reverse it after, or is there a simpler way to just write to the buffer in the right order?

.data

buffer: .space  200 
.text

main:
		la		$a1,	buffer
		li		$a2, 231
		li		$a0, 6
		jal		write_unsigned_int
exit:
		addiu      	$v0, $0, 4
		la		$a0, buffer
		syscall
		addiu		$v0, $0, 10	
		syscall	


write_unsigned_int:
		# maxlength in $a0, buffer location in $a1, and number to be printed in $a2
		addiu 		$sp, $sp, -8
		sw 		$ra,0($sp)  
		add		$s0, $0, $0 # t0 is the counter
write_loop:
		add		$t2, $0, $a2	# load contents of number
		add		$t3, $s0, $a1	# load buffer

		addiu	$t0, $0, 10
		divu	$a2, $t0
		mfhi	$t0
		addi	$t0, $t0, '0'
		mflo	$a2
		sb		$t0, 0($t3)
		beq		$a2, $0, write_unsigned_int_done
		addi	$s0, $s0, 1
		j		write_loop

write_unsigned_int_done:
		#sb		$a2, 0($t3)
		lw		$ra,0($sp)
		addiu		$sp, $sp, 8
		addu		$v0, $a0, $0
		jr		$ra

thanks in advance!