MC68HC908GZ8 Datasheet, PDF (204/344 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
17.2.3 Port A Input Pullup Enable Register
The port A input pullup enable register (PTAPUE) contains a software configurable
pullup device for each of the eight port A pins. Each bit is individually configurable
and requires that the data direction register, DDRA, bit be configured as an input.
Each pullup is automatically and dynamically disabled when a port bit’s DDRA is
configured for output mode.
Address: $000D
Bit 7
Read: _PTAPUE7
Write:
Reset:
0
6
PTAPUE6
0
5
PTAPUE5
0
4
PTAPUE4
0
3
PTAPUE3
0
2
PTAPUE2
0
1
PTAPUE1
0
Bit 0
PTAPUE0
0
Figure 17-5. Port A Input Pullup Enable Register (PTAPUE)
PTAPUE7–PTAPUE0 — Port A Input Pullup Enable Bits
These writable bits are software programmable to enable pullup devices on an
input port bit.
1 = Corresponding port A pin configured to have internal pullup
0 = Corresponding port A pin has internal pullup disconnected
17.3 Port B
Port B is an 8-bit special-function port that shares all eight of its pins with the
analog-to-digital converter (ADC) module.
17.3.1 Port B Data Register
The port B data register (PTB) contains a data latch for each of the eight port pins.
Address:
Read:
Write:
Reset:
Alternate
Function:
$0001
Bit 7
PTB7
AD7
6
PTB6
AD6
5
PTB5
AD5
4
3
PTB4
PTB3
Unaffected by reset
AD4
AD3
2
PTB2
AD2
1
PTB1
AD1
Bit 0
PTB0
AD0
Figure 17-6. Port B Data Register (PTB)
PTB7–PTB0 — Port B Data Bits
These read/write bits are software-programmable. Data direction of each port B
pin is under the control of the corresponding bit in data direction register B.
Reset has no effect on port B data.
Data Sheet
204
Input/Output (I/O) Ports
MC68HC908GZ8
Freescale Semiconductor