
Parallel Input/Output (I/O) Ports
Port A
MC68HC705J1A — Rev. 3.0
Technical Data
MOTOROLA
Parallel Input/Output (I/O) Ports
87
6.3 Port A
Port A is an 8-bit bidirectional port.
6.3.1 Port A Data Register
The port A data register (PORTA) contains a latch for each port A pin.
PA[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.
Address:
$0000
Bit 7
654321
Bit 0
Read:
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
Write:
Reset:
Unaffected by reset
Figure 6-2. Port A Data Register (PORTA)