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CPU

User Manual

UM001604-0108 Address Space

Address Space

Introduction

CPU includes the following four address spaces:

•

The Z8 Standard Register File contains addresses for peripheral, control, all general-

purpose, and all I/O port registers. This is the default register file specification.

•

The Z8 Expanded Register File (ERF) contains addresses for control and data regis-

ters for additional peripherals/features.

•

Z8 external Program Memory contains addresses for all memory locations having

executable code and/or data.

•

Z8 external data memory contains addresses for all memory locations that hold data

only, whether internal or external.

CPU Standard Register File

The Z8 Standard Register File totals up to 256 consecutive bytes (Registers). The register

file consists of 4 I/O ports (

00h–03h), 236 General-Purpose Registers (04h–EFh), and 16

control registers (

F0h–FFh). Table 2 lists the layout of the register file, including register

names, locations, and identifiers.

Table 2. Z8 Standard Register File

Hex Address

Identifier Register Description

FF SPL Stack Pointer Low Byte

FE SPH Stack Pointer High Byte

FD RP Register Pointer

FC FLAGS Program Control Flags

FB IMR Interrupt Mask Register

FA IRQ Interrupt Request Register

F9 IPR Interrupt Priority Register

F8 P01M Port 0–1 Mode Register

F7 P3M Port 3 Mode Register

F6 P2M Port 2 Mode Register

F5 PRE0 T0 Prescaler

ZiLOG Z8 Series User Manual

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