z86e54 ZiLOG Semiconductor, z86e54 Datasheet - Page 36

• Manufacturer Part Number: z86e54
• Description: Z8 512 Byte Otp Mcu
• Manufacturer: ZiLOG Semiconductor

PS020102-1003
Stack Pointer
General-Purpose Registers (GPR)
Note:
The Z8
resides within the 60 general-purpose registers from 04h to 3Fh.
These registers are undefined after the device is powered up. The registers keep
their most recent value after any reset, as long as the reset occurs in the V
age-specified operating range.
®
Register R254 is designated as a general-purpose register and
is set to 00h after any reset or Stop-Mode Recovery.
features an 8-bit Stack Pointer (R255) used for the internal stack that
FDh
FFh
F0h
3Fh
2Fh
1Fh
0Fh
30h
20h
10h
*Note: RP=00: Selects Register Group 0.
00h
This upper nibble of the register file addresses
provided by the register pointer specifies
the active working-register group.
r7 r6 r5 r4
Specified Working
Register Group 1
Register Group 0
Register Group
Figure 15.Register Pointer
I/O Ports
r3 r2 r1 r0
Must be 0
R232
(Register Pointer)
R15 to R0
The lower nibble
of the register
file addresses
provided by the
instruction points
to the specified
register.
R15 to R0
R15 to R4
R3 to R0
*
*
Z8
®
512 Byte OTP MCU
Z86E54
CC
volt-
30