z8f0813 ZiLOG Semiconductor, z8f0813 Datasheet - Page 46

• Manufacturer Part Number: z8f0813
• Description: High-performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Architecture
GPIO Alternate Functions
PS024314-0308
System
DATA
Clock
Bus
Data Register
Port Output
Figure 7
the ability to accommodate alternate functions and variable port current drive strength is
not displayed.
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 sub-registers 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.
each port pin. The alternate function associated at a pin is defined through Alternate
Function Sets sub-registers 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.
D
Q
displays a simplified block diagram of a GPIO port pin. In this figure,
Figure 7. GPIO Port Pin Block Diagram
System
Clock
Port Output Control
Port Data Direction
Table 15
Data Register
Port Input
Q
on page 39 lists the alternate functions possible with
D
Q
Z8 Encore! XP
D
General-Purpose Input/Output
Schmitt-Trigger
Product Specification
GND
VDD
®
F0823 Series
Port
Pin
36