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9.3.3
Pin Functions
Port 3 pins also function as SCI I/O pins (TxD0, RxD0, SCK0, TxD1, RxD1, and SCK1), interrupt
input pins (
IRQ4 and IRQ5), and an external expansion interrupt input pin (EXIRQ7). Port 3 pin
functions are shown in table 9-5.
Table 9-5
Port 3 Pin Functions
Pin
Pin Functions and Selection Method
P36
The pin function is switched as shown below according to the combinations of the
P36DDR bit and bit P36IRQ7E in IPINSELQ.
P36IRQ7E
0
1
P36DDR
0
1
—
Pin function
P36 input
P36 output*
EXIRQ7 input
Note: * NMOS open-drain output when P36ODR = 1.
P35/SCK1/
RQ5
The pin function is switched as shown below according to the combination of bit C/
A in
SMR of SCI1, bits CKE0 and CKE1 in SCR, and bit P35DDR.
CKE1
0
1
C/
A
01
—
CKE0
0
1
—
P35DDR
0
1
—
Pin function
P35 input
P35 output*
1
SCK1 output*
1 SCK1 output*1 SCK1 input
IRQ5 input*
2
Notes: *1 NMOS open-drain output when P35ODR = 1.
*2 When used as an external interrupt pin, do not use for another function.
P34/RxD1
The pin function is switched as shown below according to the combination of bit RE in
SCR of SCI1 and bit P34DDR.
RE
0
1
P34DDR
0
1
—
Pin function
P34 input
P34 output*
RxD1 input
Note: * NMOS open-drain output when P34ODR = 1.