MIPS Assembler

.data str: .asciiz "\nHello World!\n" # You can change what is between the quotes if you like .text .globl main main: # Do the addition # For this, we first need to put the values # to add into registers ($t0 and $t1) # You can change the 30 below to another value li $t0, 30 # You can change the 20 below to another value li $t1, 20 # Now we can add the values in $t0 # and $t1, putting the result in special register $a0 add $a0, $t0, $t1 # Set up for printing the value in $a0. # A 1 in $v0 means we want to print an integer li $v0, 1 # The system call looks at what is in $v0 # and $a0, and knows to print what is in $a0 syscall # Now we want to print Hello World # So we load the (address of the) string into $a0. # The address of the string is too big to be stored # by one instruction, so we first load the upper half, # shift it across, then load the lower half la $a0, str # And put a 4 in $v0 to mean print a string li $v0, 4 # And just like before syscall looks at # $v0 and $a0 and knows to print the string syscall # Nicely end the program li $v0, 0 jr $ra

# Define the data strings .data go_str: .asciiz "GO!!!!!\n" new_line: .asciiz "\n" .text # Where should we start? .globl main main: # Put our starting value 5 into register $t0. We will update it as we go li $t0, 5 # Put our stopping value 0 into register $t1 li $t1, 0 # This label is just used for the jumps to refer to start_loop: # This says that if the values in $t0 and $t1 are the same, # it should jump down to the end_loop label. This is the # main loop condition beq $t0, $t1, end_loop # These three lines prepare for and print the current int # It must be moved into $a0 for the printing move $a0, $t0 li $v0, 1 syscall # These three lines print a new line character so that # each number is on a new line li $v0, 4 la $a0, new_line syscall # Add -1 to the value in $t0, i.e decrement it by 1 addi $t0, $t0, -1 # Jump back up to the start_loop label j start_loop # This is the end loop label that we jump to # when the loop condition becomes true end_loop: # These three lines print the “GO!!!!” string. li $v0, 4 la $a0, go_str syscall # And these two lines make the program exit nicely li $v0, 0 jr $ra