Z8F0113 datasheet(49/245 Pages) ZILOG

49 / 245 page

PS024315-1011

P R E L I M I N A R Y

Architecture

Z8 Encore! XP® F0823 Series

Product Specification

Architecture

Figure 7 displays a simplified block diagram of a GPIO port pin. In this figure, the ability

to accommodate alternate functions and variable port current drive strength is not dis-

played.

GPIO Alternate Functions

Many of the GPIO port pins are used for general-purpose I/O and access to on-chip

peripheral functions such as the timers and serial communication devices. The port A–D

Alternate Function subregisters configure these pins for either GPIO or alternate function

operation. When a pin is configured for alternate function, control of the port pin direction

(input/output) is passed from the Port A–D Data Direction registers to the alternate func-

tion assigned to this pin. Tables 16 and 17 list the alternate functions possible with each

port pin for 8-pin and non-8-pin parts, respectively. The alternate function associated at a

pin is defined through Alternate Function Sets subregisters AFS1 and AFS2.

The crystal oscillator functionality is not controlled by the GPIO block. When the crystal

oscillator is enabled in the oscillator control block, the GPIO functionality of PA0 and PA1

is overridden. In that case, those pins function as input and output for the crystal oscillator.

Figure 7. GPIO Port Pin Block Diagram

GND

VDD

Port Output Control

Port Data Direction

Port Output

Data Register

Port Input

Data Register

Port

DATA

Bus

System

Clock

System

Clock

Schmitt-Trigger

Z8F0113 датащи(PDF) 49 Page - Zilog, Inc.