Some RISC processors include a special subroutine return pointer rather than using a stack in memory. The return address for subroutine calls is stored in this register rather than in memory. More than one level of subroutine calls requires storing and saving the contents of this register to and from memory.
  • Motorola 88100: r1 is a 32 bit register containing the return pointer generated by bsr and jsr instructions; the register can be read or overwritten by software and can even be used as a temporary general purpose data register