MC68HC908GP20 Datasheet, PDF (225/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

16.3 Port A
Port A is an 8-bit special-function port that shares all eight of its pins with
the keyboard interrupt (KBI) module. Port A also has software
configurable pullup devices if configured as an input port.
16.3.1 Port A Data Register
The port A data register (PTA) contains a data latch for each of the eight
port A pins.
Address:
Read:
Write:
Reset:
Alternate
Function:
$0000
Bit 7
PTA7
KBD7
6
PTA6
KBD6
5
4
3
2
PTA5 PTA4 PTA3 PTA2
KBD5
Unaffected by reset
KBD4 KBD3
KBD2
1
PTA1
KBD1
Figure 16-2. Port A Data Register (PTA)
Bit 0
PTA0
KBD0
PTA7–PTA0 — 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.
KBD7–KBD0 — Keyboard Inputs
The keyboard interrupt enable bits, KBIE7–KBIE0, in the keyboard
interrupt control register (KBICR) enable the port A pins as external
interrupt pins. See Section 13. Keyboard Interrupt Module (KBI).
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor
Advance Information
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