- R2: commonly used as return value
- R6, R7: by uP design, used as loop counters
- A8: mostly often points to #IOBASE
- R9: mostly often equal to 0
- A10: commonly used for pointer input parameter
- A11: commonly used for pointer input parameter
- A14: return adress, specified as such in the datasheet.
- A15: stack pointer, by uP design.
- T flag: used to return boolean values
Register pairs used for 32 bit value are always in the form
[ R(n+1) : R(n) ] where n is an even number. examples R1R0, R3R2.
