Datasheet

Section 8 I/O Ports
Rev. 3.00 Sep. 28, 2009 Page 162 of 710
REJ09B0384-0300
8.9 Port A
Port A is an 8-bit I/O port. Port A pins also function as event counter input. Pin functions are
switched depending on the operating mode. Port A has the following registers.
• Port A data direction register (PADDR)
• Port A output data register (PAODR)
• Port A input data register (PAPIN)
8.9.1 Port A Data Direction Register (PADDR)
The individual bits of PADDR specify input or output for the pins of port A.
Bit Bit Name Initial Value R/W Description
7 PA7DDR 0 W
6 PA6DDR 0 W
5 PA5DDR 0 W
4 PA4DDR 0 W
3 PA3DDR 0 W
2 PA2DDR 0 W
1 PA1DDR 0 W
The corresponding port A pins function as output port
when the PADDR bits are set to 1, and as input port
when cleared to 0.
This register is assigned to the same address as that
of PAPIN. When this address is read, the port A
states are returned.
0 PA0DDR 0 W