Z8F4822AR020SG Datasheet, PDF (62/323 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F64xx Series
Product Specification
42
Port A–H Alternate Function Subregisters
The Port A–H Alternate Function Subregister, shown in Table 17, is accessed through the 
Port A–H Control Register by writing 02H to the Port A–H Address Register. The Port A–
H Alternate Function subregisters select the alternate functions for the selected pins. To
determine the alternate function associated with each port pin, see the GPIO Alternate
Functions section on page 37.
Caution: Do not enable alternate function for GPIO port pins which do not have an associated al-
ternate function. Failure to follow this guideline may result in unpredictable operation.
Table 17. Port A–H Alternate Function Subregisters
Bit
7
6
5
4
3
2
1
0
Field
AF7
AF6
AF5
AF4
AF3
AF2
AF1
AF0
RESET
0
R/W
R/W
Address
See note.
Note: If a 02H exists in the Port A–H Address Register, it is accessible through the Port A–H Control Register.
Bit
Description
[7:0]
AFx
Port Alternate Function Enabled
0 = The port pin is in NORMAL Mode and the DDx bit in the Port A–H Data Direction Subregis-
ter determines the direction of the pin.
1 = The alternate function is selected. Port pin operation is controlled by the alternate function.
Note: x indicates register bits in the range [7:0].
PS019924-0113
PRELIMINARY
GPIO Control Register Definitions