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Section 8 I/O Ports
8.1.3
Port 3
Port 3 is an 8-bit I/O port. Port 3 pins can also function as the bidirectional data bus and de-
bounced input pins. The pin functions change according to the operating mode. Port 3 has the
following registers.
• Port 3 data direction register (P3DDR)
• Port 3 data register (P3DR)
• Port 3 pull-up MOS control register (P3PCR)
• Noise canceler enable register (P3NCE)
• Noise canceler mode control register (P3NCMC)
• Noise cancel cycle setting register (NCCS)
(1)
Port 3 Data Direction Register (P3DDR)
The individual bits of P3DDR specify input or output for the port 3 pins.
Bit
Bit Name
7
P37DDR
6
P36DDR
5
P35DDR
4
P34DDR
3
P33DDR
2
P32DDR
1
P31DDR
0
P30DDR
Rev. 1.00 Mar. 12, 2008 Page 200 of 1178
REJ09B0403-0100
Initial Value
R/W Description
0
W
0
W
0
W
0
W
0
W
0
W
0
W
0
W
•
Normal extended mode (ADMXE = 0)
The pins function as bidirectional data bus pins.
•
Other modes
When set to 1, the corresponding pins function as
output port pins; when cleared to 0, function as input
port pins.
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