mc68hc908rf2 Freescale Semiconductor, Inc, mc68hc908rf2 Datasheet - Page 108

• Manufacturer Part Number: mc68hc908rf2
• Description: M68hc08 Microcontrollers Microcontroller / Transmitter
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
9.2 Port A
9.2.1 Port A Data Register
Data Sheet
108
NOTE:
Alternate Function:
Port A is an 8-bit special function port that shares six of its pins with the keyboard
interrupt module (KBD). PTA6–PTA1 contain pullup resistors enabled when the
port pin is enabled as a keyboard interrupt. Port A pins are also high-current port
pins with 3-mA sink capabilities.
The port A data register (PTA) contains a data latch for each of the eight port A
pins.
PTA[7:0] — Port A Data Bits
KBD[6:1] — Keyboard Wakeup Pins
The enabling of a keyboard interrupt pin will override the corresponding definition
of the pin in the data direction register. However, the data direction register bit must
be a 0 for software to read the pin.
These read/write bits are software programmable. Data direction of each port A
pin is under the control of the corresponding bit in data direction register A.
Reset has no effect on port A data.
The keyboard interrupt enable bits, KBIE[6:1], in the keyboard interrupt control
register enable the port A pin as external interrupt pins and related internal
pullup resistor. See
Address:
Reset:
Read:
Write:
Freescale Semiconductor, Inc.
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PTA7
Bit 7
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Figure 9-2. Port A Data Register (PTA)
= Unimplemented
Input/Output (I/O) Ports
KBD6
PTA6
Section 7. Keyboard/External Interrupt Module
6
KBD5
PTA5
5
Unaffected by reset
PTA4
KBD4
4
PTA3
KBD3
3
PTA2
KBD2
MC68HC908RF2 — Rev. 4.0
2
KBD1
PTA1
1
MOTOROLA
(KBI).
PTA0
Bit 0