Z86E30/E31/E40
Z8 4K OTP Microcontroller
Zilog
1
r7 r6 r5 r4
r3 r2 r1 r0
R253
(Register Pointer)
The upper nibble of the register file address
provided by the register pointer specifies
the active working-register group.
FF
Register Group F
F0
EF
Note: Registers 80H
through EFH are
available in the Z86C30
only.
80
7F
70
6F
60
5F
50
4F
The lower nibble
of the register
file address
provided by the
instruction points
to the specified
register.
40
3F
Specified Working
Register Group
30
2F
20
1F
Register Group 1
R15 to R0
10
0F
R15 to R4*
R3 to R0*
Register Group 0
I/O Ports
00
* Expanded Register Group (0) is selected
in this figure by handling bits D3 to D0 as
"0" in Register R253 (RP).
Figure 25. Register Pointer
DS97Z8X0500
P R E L I M I N A R Y
35
ZILOG [ ZILOG, INC. ]
