MC68HC908GP32 Datasheet, PDF (214/410 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Freescale Semiconductor, Inc.
Input/Output (I/O) Ports
16.2 Introduction
Thirty-three (33) bidirectional input-output (I/O) pins form five parallel
ports. All I/O pins are programmable as inputs or outputs. All individual
bits within port A, port C, and port D are software configurable with pullup
devices if configured as input port bits. The pullup devices are
automatically and dynamically disabled when a port bit is switched to
output mode.
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. Register Name
Bit 7
6
5
4
3
$0000
Read:
Port A Data Register
(PTA)
Write:
Reset:
PTA7
PTA6 PTA5 PTA4 PTA3
Unaffected by reset
$0001
Read:
Port B Data Register
(PTB)
Write:
Reset:
PTB7
PTB6 PTB5 PTB4 PTB3
Unaffected by reset
$0002
Read: 0
Port C Data Register
(PTC)
Write:
Reset:
PTC6 PTC5 PTC4 PTC3
Unaffected by reset
$0003
Read:
Port D Data Register
(PTD)
Write:
Reset:
PTD7
PTD6
PTD5 PTD4 PTD3
Unaffected by reset
Read:
$0004
Data Direction Register A
(DDRA)
Write:
Reset:
DDRA7
0
DDRA6
0
DDRA5
0
DDRA4
0
DDRA3
0
= Unimplemented
Figure 16-1. I/O Port Register Summary
2
PTA2
PTB2
PTC2
PTD2
DDRA2
0
1
PTA1
PTB1
PTC1
PTD1
DDRA1
0
Bit 0
PTA0
PTB0
PTC0
PTD0
DDRA0
0
Technical Data
212
MC68HC908GP32•MC68HC08GP32 — Rev. 6
Input/Output (I/O) Ports
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