M68HC08 Datasheet, PDF (107/188 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Data Sheet — MC68HC908RF2
Section 9. Input/Output (I/O) Ports
9.1 Introduction
Twelve bidirectional input/output (I/O) pins form two parallel ports in the 32-pin
low-profile quad flat pack (LQFP). All I/O pins are programmable as inputs or
outputs. Port A bits PTA6–PTA1 have keyboard wakeup interrupts and internal
pullup resistors.
NOTE:
Connect any unused I/O pins to an appropriate logic level, either V_DD or V_SS.
Although the I/O ports do not require termination for proper operation, termination
reduces excess current consumption and the possibility of electrostatic damage.
Addr.
$0000
$0001
$0004
$0005
Register Name
Bit 7
Port A Data Register ^Read:
(PTA) Write:
See page 108. _Reset:
PTA7
Port B Data Register ^Read:
(PTB) Write:
See page 110. _Reset:
Data Direction Register A ^Read:
(DDRA) Write:
See page 109. _Reset:
DDRA7
0
Data Direction Register B ^Read: _MCLKEN
(DDRB) Write:
See page 111. _Reset:
0
6
PTA6
5
PTA5
DDRA6
0
0
DDRA5
0
0
0
= Unimplemented
4
3
PTA4
PTA3
Unaffected by reset
PTB3
Unaffected by reset
DDRA4 DDRA3
0
0
DDRB3
0
0
Figure 9-1. I/O Port Register Summary
2
PTA2
PTB2
DDRA2
0
DDRB2
0
1
PTA1
PTB1
DDRA1
0
DDRB1
0
Bit 0
PTA0
PTB0
DDRA0
0
DDRB0
0
MC68HC908RF2 — Rev. 4.0
MOTOROLA
Input/Output (I/O) Ports
For More Information On This Product,
Go to: www.freescale.com
Data Sheet
107