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PORT3 is an 8-bit read-only register that shows the pin states. It cannot be written to. Writing of
output data for the port 3 pins (P36 to P30) must always be performed on P3DR. Bit 7 is reserved;
this bit cannot be modified and will return an undefined value if read.
If a port 3 read is performed while P3DDR bits are set to 1, the P3DR values are read. If a port 3
read is performed while P3DDR bits are cleared to 0, the pin states are read.
After a power-on reset and in hardware standby mode, PORT3 contents are determined by the pin
states, as P3DDR and P3DR are initialized. PORT3 retains its previous state after a manual reset
and in software standby mode.
(4) Port 3 Open-Drain Control Register (P3ODR)
7
—
Undefined
—
6
P36ODR
0
R/W
5
P35ODR
0
R/W
4
P34ODR
0
R/W
3
P33ODR
0
R/W
0
P30ODR
0
R/W
2
P32ODR
0
R/W
1
P31ODR
0
R/W
Bit
:
Initial value :
R/W
:
P3ODR is an 8-bit readable/writable register that controls the PMOS on/off status for each port 3
pin (P36 to P30). Bit 7 is reserved; this bit cannot be modified and will return an undefined value
if read.
Setting a P3ODR bit to 1 makes the corresponding port 3 pin an NMOS open-drain output pin,
while clearing the bit to 0 makes the pin a CMOS output pin.
P3ODR is initialized to H'00 by a power-on reset and in hardware standby mode. It retains its
previous state after a manual reset and in software standby mode.
(5) Interrupt Request Input Pin Select Register 0 (IPINSEL0)
Bit
:
7
65
43
21
0
P36
IRQ7E
P47
IRQ6E
P46
IRQ5E
P44
IRQ4E
P43
IRQ3E
P42
IRQ2E
P41
IRQ1E
P40
IRQ0E
Initial value :
0
R/W
:
R/W
IPINSEL0 is an 8-bit readable/writable register that selects which pins are to be used for interrupt
request input signals (
EXIRQ0 to EXIRQ7) from externally connected modules. IPINSEL0 is
initialized to H'00 by a power-on reset and in hardware standby mode. It retains its previous state
in a manual reset and in software standby mode.