Datasheet

Section 8 I/O Ports
Rev. 2.00 Aug. 20, 2008 Page 315 of 1198
REJ09B0403-0200
8.2.8 Port 8
Port 8 is an 8-bit I/O port. Port 8 pins can also function as the A/D converter external trigger input,
SCI_1 and SCI_3 input/output, IIC_0 and IIC_1 input/output, and interrupt input pins. Pins 83 to
80 perform the NMOS push-pull output. Port 8 has the following registers.
• Port 8 data direction register (P8DDR)
• Port 8 data register (P8DR)
(1) Port 8 Data Direction Register (P8DDR)
The individual bits of P8DDR specify input or output for the port 8 pins.
Bit Bit Name Initial Value R/W Description
7 P87DDR 0 W
6 P86DDR 0 W
5 P85DDR 0 W
4 P84DDR 0 W
3 P83DDR 0 W
2 P82DDR 0 W
1 P81DDR 0 W
0 P80DDR 0 W
If port 8 pins are specified for use as the general I/O
port, the corresponding pins function as output port
when the P8DDR bits are set to 1, and as input port
when cleared to 0.
Since this register is allocated to the same address as
PBPIN, states of the port 8 pins are when this register
is read.