Datasheet

Port A
MC68HC908JL3E Family Data Sheet, Rev. 4
Freescale Semiconductor 105
10.2 Port A
Port A is an 7-bit special function port that shares all seven of its pins with the keyboard interrupt (KBI)
module (see Chapter 12 Keyboard Interrupt Module (KBI)). Each port A pin also has software configurable
pull-up device if the corresponding port pin is configured as input port. PTA0 to PTA5 has direct LED drive
capability.
NOTE
PTA0–PTA5 pins are available on MC68H(R)C908JL3E only.
PTA6 pin is available on MC68HRC908JL3E/JK3E/JK1E only.
10.2.1 Port A Data Register (PTA)
The port A data register (PTA) contains a data latch for each of the seven port A pins.
PTA[6:0] — Port A Data Bits
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.
KBI[6:0] — Port A Keyboard Interrupts
The keyboard interrupt enable bits, KBIE[6:0], in the keyboard interrupt control register (KBIER) enable
the port A pins as external interrupt pins, (see Chapter 12 Keyboard Interrupt Module (KBI)).
Address: $0000
Bit 76 5 4 3 2 1Bit 0
Read: 0
PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0
Write:
Reset: Unaffected by Reset
Additional Functions:
LED
(Sink)
LED
(Sink)
LED
(Sink)
LED
(Sink)
LED
(Sink)
LED
(Sink)
30k pull-up 30k pull-up 30k pull-up 30k pull-up 30k pull-up 30k pull-up 30k pull-up
Keyboard
Interrupt
Keyboard
Interrupt
Keyboard
Interrupt
Keyboard
Interrupt
Keyboard
Interrupt
Keyboard
Interrupt
Keyboard
Interrupt
= Unimplemented
Figure 10-2. Port A Data Register (PTA)