MC68HC908LD64 Datasheet, PDF (297/362 Pages) Freescale Semiconductor, Inc – Microcontrollers

19.3 Port A
Input/Output (I/O) Ports
Port A
Port A is an 8-bit special-function port that shares all eight of its pins with
the keyboard interrupt module (KBI). (See Section 21. Keyboard
Interrupt Module (KBI).)
19.3.1 Port A Data Register
The port A data register (PTA) contains a data latch for each of the eight
port A pins.
Address: $0000
Bit 7
6
5
4
3
2
1
Bit 0
Read:
PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0
Write:
Reset:
Unaffected by reset
Alternative Function: KBI7
KBI6
KBI5
KBI4
KBI3
KBI2
KBI1
KBI0
Figure 19-2. Port A Data Register (PTA)
PTA[7:0] — 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[7:0] — Keyboard Interrupt Pins
The keyboard interrupt enable bits, KBIE[7:0], in the keyboard
interrupt enable register (KBIER), enable the port A pins as external
interrupt pins. (See 19.3.3 Port A Options and Section 21.
Keyboard Interrupt Module (KBI).)
MC68HC908LD64 — Rev. 3.0
Freescale Semiconductor
Input/Output (I/O) Ports
Data Sheet
297