2. Registers may not have the value 0 when the program starts execution - clear them using AND R0, R0, #0 before using them as source operands in any instruction
3. Every program needs to have a TRAP x25 instruction to stop execution.
4. If you need to set the condition codes depending on the value in a certain register (so that a branch instruction can follow), you can use:
ADD R0, R0, #0 or AND R0, R0, -1 (xFFFF)This is a better option than storing a register to memory & loading it back to set the condition codes.