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10.3
Port 3
10.3.1
Overview
Port 3 is an 8-bit I/O port. Port 3 is a multi-purpose port for SCI I/O pins (TxD0, RxD0, SCK0,
IrTxD, IrRxD, TxD1, RxD1, SCK1, TxD4, RxD4, SCK4), external interrupt input pins (IRQ4,
IRQ5) and IIC I/O pins (SCL0, SDA0, SCL1, SDA1). All of the port 3 pin functions have the
same operating mode. The configuration for each of the port 3 pins is shown in figure 10-2.
Port 3
10.3.2
Register Configuration
Table 10-4 shows the configuration of port 3 registers.
Table 10-4 Port 3 Register Configuration
Name
Port 3 data direction register
Port 3 data register
Port 3 register
Port 3 open drain control register
Note: * Indicates the lower-place 16 bits.
Port 3 pins
P37
(input / output) /
TxD4 (output)
P36
(input / output) /
RxD4 (input)
P35
(input / output) /
SCK1 (input / output)
/ SCK4 (input / output) / SCL0 (input / output) / IRQ5 (input)
P34
(input / output) /
RxD1 (input) / SDA0 (input / output)
P33
(input / output) /
TxD1 (input) / SCL1 (input / output)
P32
(input / output) /
SCK0 (input / output) / SDA1 (input / output) / IRQ4 (input)
P31
(input / output) /
RxD0 (input) / IrRxD (input)
P30
(input / output) /
TxD0 (output) / IrTxD (output)
Figure 10-2 Port 3 Pin Functions
Abbreviation
R/W
P3DDR
W
P3DR
R/W
PORT3
R
P3ODR
R/W
Initial Value
Address*
H'00
H'FE32
H'00
H'FF02
Undefined
H'FFB2
H'00
H'FE46
347
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