Z86L88 Datasheet, PDF (39/80 Pages) Zilog, Inc. – INFRARED REMOTE CONTROLLERS

Z86L88
Low-Voltage IR Microcontroller
32
R253 RP
D7 D6 D5 D4 D3 D2 D1 D0
Default setting after
reset = 0000 0000
Expanded Register Bank
Pointer
Working Register
Pointer
Figure 27. Register Pointer—FDH: Read/Write
R254 SPH
D7 D6 D5 D4 D3 D2 D1 D0
General-Purpose Register
Byte (SP15–SP8)
Figure 28. Stack Pointer High—FEH: Read/Write
R255 SPL
D7 D6 D5 D4 D3 D2 D1 D0
Stack Pointer Lower
Byte (SP7–SP0)
Figure 29. Stack Pointer Low—FFH: Read/Write
Register File
The register file (bank 0) consists of 4 I/O port registers, 237 general-purpose reg-
isters, and 16 control and status registers (R0–R3, R4–R239, and R240–255,
respectively). Additionally, there are two expanded registers groups in Banks D
and F. Instructions can access registers directly or indirectly through an 8-bit
address field, thereby allowing a short, 4-bit register address to use the Register
Pointer (Figure 30). In the 4-bit mode, the register file is divided into 16 working
register groups, each occupying 16 continuous locations. The Register Pointer
addresses the starting location of the active working register group.
Note: Working register group E0–EF can only be accessed through
working registers and indirect addressing modes.
19-4614; Rev 0; 4/09