cpik uses 6 16 bit pseudo-registers named R0,R1,R2,R3,R4 and R5. These registers are located in page 0, and are efficiently accessed via Access Bank (a=0).
W
is used as a general purpose scratch register
R0
is the 16 bit equivalent of W,
R1
to R5
are used by the Run-time library (RTL),
FSR0
is the software stack pointer,
FSR1
is a general purpose address register,
FSR2
is used for fast memory moves together with FSR1,
PRODL
and PRODH
are used for arithmetics and temporaries
INDFx
, PREINCx
, POSTDECx
, and PLUSWx
are intensively used
and also accessed in Access Bank for efficiency reasons.