z8f083a ZiLOG Semiconductor, z8f083a Datasheet - Page 27

• Manufacturer Part Number: z8f083a
• Description: High-performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Address Space
Register File
Program Memory
PS026308-1207
The eZ8 CPU accesses three distinct address spaces as follows:
•
•
•
The following sections describe about these three address spaces. For more detailed
information on the eZ8 CPU and its address space, refer to eZ8 CPU User Manual
available for download at www.zilog.com.
The Register File address space in the Z8 Encore! MCU is 4 KB (4096 bytes). The
Register File consists of two sections: control registers and general purpose registers.
When instructions are executed, registers defined as source are read and registers defined
as destinations are written. The architecture of the eZ8 CPU allows all general purpose
registers to function as accumulators, address pointers, index registers, stack areas, or
scratch pad memory.
The upper 256 bytes of the 4 KB Register File address space are reserved for control of the
eZ8 CPU, on-chip peripherals, and the I/O ports. These registers are located at addresses
from
reserved (unavailable). Reading from a reserved Register File address returns an
undefined value. Writing to reserved Register File addresses is not recommended and
produces unpredictable results.
The on-chip RAM always begins at address
Z8 Encore! F083A Series devices contain up to 256 B 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 has no effect.
The eZ8 CPU supports 64 KB of program memory address space. The Z8 Encore! F083A
Series devices contain 1 KB to 12 KB of on-chip Flash memory in the program memory
address space, depending on the device. Reading from program memory addresses outside
The Register File addresses access for the general purpose registers and the eZ8 CPU,
peripheral, and GPIO port control registers.
The Program Memory addresses access for all the memory locations having executable
code and/or data.
The Data Memory addresses access for all the memory locations containing only the data.
F00H
to
FFFH
. Some of the addresses within the 256 B control register section are
000H
in the Register File address space. The
Z8 Encore!
Product Specification
®
F083A Series
Address Space
15