Zilog Z86193 - Manual (Page 237)

Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
230
group of 16 registers. Registers
F0h
to
FFh
can be accessed as Working Registers R0 to
R15.
Example 3
The statement:
SRP 0Fh
Op Code: 31 0F
sets the Register Pointer to access Expanded Register Bank F, Reg ← to Reg
0Fh
, as the
current Working Registers. All references to Working Registers now affect this group of
16 registers. These registers are now accessed as Working Registers R0 to R15. Port Reg-
isters are now not accessable.
Example 4
Assume the RP currently addresses the Control and Peripheral Working Register Group
and the program has just entered an interrupt service routine. The statement:
SRP 70h
Op Code: 31 70
retains the contents of the Control and Peripheral Registers by setting the RP to
70h
(
01110000b
). Any reference to Working Registers in the interrupt routine points to regis-
ters
70h
to
7Fh
.