z8f0822 ZiLOG Semiconductor, z8f0822 Datasheet - Page 26

• Manufacturer Part Number: z8f0822
• Description: High Performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Address Space
Register File
Program Memory
PS022517-0508
The eZ8 CPU accesses three distinct address spaces:
•
•
•
These three address spaces are covered briefly in the following sections. For more infor-
mation on the eZ8 CPU and its address space, refer to eZ8 CPU Core User Manual
(UM0128) available for download at www.zilog.com.
The Register File address space in the Z8 Encore! XP
posed of two sections—Control Registers and General-Purpose Registers. When instruc-
tions are executed, registers are read from when defined as sources and written to when
defined as destinations. The architecture of the eZ8 CPU allows all general-purpose regis-
ters to function as accumulators, address pointers, index registers, stack areas, or scratch
pad memory.
The upper 256 bytes of the 1 KB Register File address space is reserved for control
of the eZ8 CPU, the on-chip peripherals, and the I/O ports. These registers are located at
addresses from
section is reserved (unavailable). Reading from the reserved Register File addresses
returns an undefined value. Writing to reserved Register File addresses is not recom-
mended and can produce unpredictable results.
The on-chip RAM always begins at address
Z8 Encore! XP F0822 Series contains 1 KB of on-chip RAM. Reading from Register File
addresses outside the available RAM addresses (and not within the control register address
space) returns an undefined value. Writing to these Register File addresses produces no
effect.
The eZ8 CPU supports 64 KB of Program Memory address space. Z8 Encore! XP
Series contain 4 KB to 8 KB on-chip Flash in the Program Memory address space,
depending on the device. Reading from Program Memory addresses outside the available
Flash addresses returns
duces no
Series devices.
The
the eZ8 CPU, Peripheral, and GPIO Port Control Registers.
The
code and/or data.
The
Register File
Program Memory
Data Memory
effect.
F00H
Table 5
to
contains addresses for the general-purpose registers and
contains addresses for all memory locations that hold data only.
FFH
FFFH
describes the Program Memory Maps for Z8 Encore! XP F0822
contains addresses for all memory locations having executable
. Writing to unimplemented Program Memory addresses pro-
. Some of the addresses within the 256-byte Control Register
000H
in the Register File address space.
®
is 4 KB (4096 bytes). It is com-
Z8 Encore! XP
Product Specification
®
F0822 Series
Address Space
®
F0822
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