Datasheet

Section 9 I/O Ports
Rev. 3.00 Sep. 14, 2006 Page 123 of 408
REJ09B0105-0300
9.2.3 Pin Functions
The correspondence between the register specification and the port functions is shown below.
• P22/TXD pin
Register PMR1 PCR2
Bit Name TXD PCR22 Pin Function
Setting
value
0 0 P22 input pin
1 P22 output pin
1 X TXD output pin
[Legend]
X: Don't care
• P21/RXD pin
Register SCR3 PCR2
Bit Name RE PCR21 Pin Function
Setting
value
0 0 P21 input pin
1 P21 output pin
1 X RXD input pin
[Legend]
X: Don't care
• P20/SCK3 pin
Register SCR3 SMR PCR2
Bit Name CKE1 CKE0 COM PCR20 Pin Function
Setting value 0 0 0 0 P20 input pin
1 P20 output pin
0 0 1 X SCK3 output pin
0 1 X X SCK3 output pin
1 X X X SCK3 input pin
[Legend]
X: Don't care