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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
7
P87DDR
6
P86DDR
5
P85DDR
4
P84DDR
3
P83DDR
2
P82DDR
1
P81DDR
0
P80DDR
Initial Value
R/W
0
W
0
W
0
W
0
W
0
W
0
W
0
W
0
W
Description
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.
Rev. 1.00 Mar. 12, 2008 Page 313 of 1178
Section 8 I/O Ports
REJ09B0403-0100
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