Instruction Set Architecture—IP2022 User’s Manual 64 www.ubicom.com decsnz)  generates  a  borrow,  the  high  part  of  the  register  is decremented.   Because   carry   and   borrow   are   automatically
handled,  the  addc  and  subc  instructions  are  not  needed  for
arithmetic on pointer registers. 3.1.2 Direct Addressing Mode Figure 3-2 shows the direct addressing mode used to reference
the special-purpose registers. Seven bits from the “fr” field allow
addressing  up  to  128  special-purpose  registers.  (Not  all  128
locations  in  this  space  are  implemented  in  the  IP2022;  several
locations are reserved for future expansion.) Figure 3-2  Direct Addressing, Special-Purpose Registers The following code example uses direct addressing. mov w,0x012 ;load W with the contents of
;the memory location at 0x012
;(the DATAL register) 515-007.eps             128
Special-Purpose Registers 7 0   9-Bit "fr" Field
from Instruction 0 8 0 n n n n n n n 0 7 6