mc68hc908qf4 Freescale Semiconductor, Inc, mc68hc908qf4 Datasheet - Page 112

• Manufacturer Part Number: mc68hc908qf4
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
13.2 Port A
13.2.1 Port A Data Register
Data Sheet
112
NOTE:
Additional Functions:
Port A is a 6-bit special function port that shares all six of its pins with the keyboard
interrupt (KBI) module (see
port A pin also has a software configurable pullup device if the corresponding port
pin is configured as an input port.
PTA2 is input only.
When the IRQ function is enabled in the configuration register 2 (CONFIG2), bit 2
of the port A data register (PTA) will always read a 0. In this case, the BIH and BIL
instructions can be used to read the logic level on the PTA2 pin. When the IRQ
function is disabled, these instructions will behave as if the PTA2 pin is a logic 1.
However, reading bit 2 of PTA will read the actual logic level on the pin.
The port A data register (PTA) contains a data latch for each of the six port A pins.
PTA[5:0] — Port A Data Bits
AWUL — Auto Wakeup Latch Data Bit
KBI[5:0] — Port A Keyboard Interrupts
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.
This is a read-only bit which has the value of the auto wakeup interrupt request
latch. The wakeup request signal is generated internally (see
Wakeup Module
such as PTA6 data register, pullup enable or direction.
The keyboard interrupt enable bits, KBIE5–KBIE0, in the keyboard interrupt
control enable register (KBIER) enable the port A pins as external interrupt pins
(see
Address: $0000
Reset:
Read:
Write:
Freescale Semiconductor, Inc.
Section 9. Keyboard Interrupt Module
For More Information On This Product,
Bit 7
R
R
Figure 13-2. Port A Data Register (PTA)
Go to: www.freescale.com
Input/Output (I/O) Ports
= Reserved
(AWU)). There is no PTA6 port nor any of the associated bits
AWUL
6
Section 9. Keyboard Interrupt Module
PTA5
KBI5
5
Unaffected by reset
PTA4
KBI4
4
= Unimplemented
PTA3
KBI3
(KBI)).
3
PTA2
MC68HC908QF4 — Rev. 1.0
KBI2
2
Section 4. Auto
PTA1
KBI1
1
(KBI)). Each
MOTOROLA
PTA0
KBI0
Bit 0