Datasheet

Section 10 I/O Ports
Rev. 6.00 Mar. 18, 2010 Page 321 of 982
REJ09B0054-0600
• P30/TxD0
The pin functions are switched as shown below according to the combination of the TE bit in
SCR_0 of SCI_0 and the P30DDR bit.
TE 0 1
P30DDR 0 1 ⎯
Pin functions P30 input pin P30 output pin
*
TxD0 output
*
Note: * When P30ODR is set to 1, it functions as NMOS open drain output.
10.3 Port 4
Port 4 is an 8-bit input port and has the following register.
• Port 4 register (PORT4)
10.3.1 Port 4 Register (PORT4)
PORT4 shows port 4 pin states.
Bit Bit Name Initial Value R/W Description
7 P47 —
*
R
6 P46 —
*
R
5 P45 —
*
R
4 P44 —
*
R
3 P43 —
*
R
2 P42 —
*
R
1 P41 —
*
R
The pin states are always read when a port 4 read
is performed.
0 P40 —
*
R
Note: * Determined by the states of pins P47 to P40.
10.3.2 Pin Functions
Port 4 pins also function as A/D converter analog input pins (AN7 to AN0).