z86c96 ZiLOG Semiconductor, z86c96 Datasheet - Page 28

• Manufacturer Part Number: z86c96
• Description: Cmos Z8 Microcontroller
• Manufacturer: ZiLOG Semiconductor

FUNCTIONAL DESCRIPTION (Continued)
Z86C61/62/96
CMOS Z8 Microcontroller
Register File. The Register File consists of four I/O port
registers, 236 general-purpose registers and 16 control
and status registers (Figure 18). There are eight further
registers for I/O ports 4, 5 and 6 in the Expanded Register
File (Bank F, R9-R2) (Figure 20).
The instructions can access registers directly or indirectly
through an 8-bit address field. The Z86C61/62/96 also al-
lows short 4-bit register addressing using the Register
Pointer (Figure 21). 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: Register Bank E0-EF can only be accessed through
working registers and indirect addressing modes.
28
Default Setting After Reset = 00000000
R253
D7 D6 D5 D4 D3 D2 D1 D0
RP
Figure 21. Register Pointer Register
Expanded Register Group
Working Register Group
PS003501-0301
P R E L I M I N A R Y
Location
R255
R254
R253
R252
R251
R250
R249
R248
R247
R246
R245
R244
R243
R242
R241
R240
R239
R4
R3
R2
R1
R0
Figure 22. Register File
Interrupt Request Register
Interrupt Priority Register
Stack Pointer (Bits 15-8)
Stack Pointer (Bits 7-0)
Interrupt Mask Register
Program Control Flags
General-Purpose
Register Pointer
Timer/Counter0
Timer/Counter1
Ports 0-1 Mode
T0 Prescaler
T1 Prescaler
Port 3 Mode
Port 2 Mode
Timer Mode
Serial I/O
Registers
Port 3
Port 2
Port 1
Port 0
DS97Z8X1600
Identifiers
SPL
SPH
RP
FLAGS
IMR
IRQ
IPR
P01M
P3M
P2M
PRE0
T0
PRE1
T1
TMR
SIO
P3
P2
P1
P0
Zilog