mov   dptr,#SetbAddr     ;address in "vonNeummann" external RAM
   mov   a,#0D2h      ;opcode for setb
   movx  @dptr,a
   inc   dptr
   mov   a,r0         ;our bit address
   movx  @dptr,a
   inc   dptr
   mov   a,#22        ;opcode for ret
   movx  @dptr,a
   lcall SetbAddr