Indirect Addressing mode

+-------+-----+
   |jumpVia| reg | 
   +-------+-----+
   
   (Effective PC address = contents of register 'reg')

The effective address for a Register indirect instruction is the address in the specified register. For example, (A7) to access the content of address register A7.

The effect is to transfer control to the instruction whose address is in the specified register.

Many RISC machines have a subroutine call instruction that places the return address in an address register—the register indirect addressing mode is used to return from that subroutine call.