Complete Program

Here is the complete program, suitable to copy to a file and to run with SPIM. When you run it, set the PC to 0x400000 (as usual) and also use the set value menu to set $2 to a temperature. Run the program with different temperatures and check that $3 is set correctly.

## tempRange.asm
##
## Check that   30 <= temp <= 55
## Set flag to 1 if in range, to 0 if out of range
##
## Registers:
## $2 --- temperature
## $3 --- in/out range indicator flag
## $8 --- scratch

      .text
      .globl  main

# Set range indicator to 1
main:   ori     $3,$0,1         #  set to 1

# Test  30 <= temp <= 55
        sltiu   $8,$2,56        #  $8=1 if temp <= 55
        beq     $8,$0,out       #  0? out of range
        sll     $0,$0,0         #  delay

        sltiu   $8,$2,30        #  $8=1 if  temp < 30
        beq     $8,$0,cont      #  0? in range
        sll     $0,$0,0         #  delay

# Out of Range: clear range indicator to 0
out:    ori     $3,$0,0         #  clear flag to 0

cont:   sll     $0,$0,0         #  target for the jump