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Section 8 I/O Ports
8.2.9
Port 9
Port 9 is an 8-bit I/O port. Port 9 pins can function as the bus control input/output pins. The pin
functions change according to the operating mode. Port 9 has the following registers.
• Port 9 data direction register (P9DDR)
• Port 9 data register (P9DR)
(1)
Port 9 Data Direction Register (P9DDR)
The individual bits of P9DDR specify input or output for the port 9 pins.
Bit
Bit Name
7
P97DDR
6
P96DDR
5
P95DDR
4
P94DDR
3
P93DDR
2
P92DDR
1
P91DDR
0
P90DDR
Rev. 1.00 Mar. 12, 2008 Page 318 of 1178
REJ09B0403-0100
Initial Value
R/W
0
W
0
W
0
W
0
W
0
W
0
W
0
W
0
W
Description
If port 9 pins are specified for use as the general I/O
port, the corresponding pins function as output port
when the P9DDR bits are set to 1, and as input port
when cleared to 0.
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