HD64F36024FX Datasheet, PDF (129/386 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 9 I/O Ports
9.2.2 Port Data Register 2 (PDR2)
PDR2 is a general I/O port data register of port 2.
Bit
7 to 3
Bit Name

Initial
Value
All 1
2
P22
0
1
P21
0
0
P20
0
R/W

R/W
R/W
R/W
Description
Reserved
These bits are always read as 1.
PDR2 stores output data for port 2 pins.
If PDR2 is read while PCR2 bits are set to 1, the value
stored in PDR2 is read. If PDR2 is read while PCR2 bits
are cleared to 0, the pin states are read regardless of the
value stored in PDR2.
9.2.3 Pin Functions
The correspondence between the register specification and the port functions is shown below.
• P22/TXD pin
Register
PMR1
Bit Name TXD
Setting Value 0
1
Legend X: Don't care.
PCR2
PCR22
0
1
X
Pin Function
P22 input pin
P22 output pin
TXD output pin
• P21/RXD pin
Register
SCR3
Bit Name RE
Setting Value 0
1
Legend X: Don't care.
PCR2
PCR21
0
1
X
Pin Function
P21 input pin
P21 output pin
RXD input pin
Rev. 4.00 Sep. 23, 2005 Page 101 of 354
REJ09B0025-0400