h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 263

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

8.4.2
Table 8.7 shows the port 3 register configuration.
Table 8.7
Note:
Port 3 Data Direction Register (P3DDR)
P3DDR is an 8-bit write-only register, the individual bits of which specify input or output for the
pins of port 3. P3DDR cannot be read; if it is, an undefined value will be returned.
P3DDR is initialized to H'00 by a reset and in hardware standby mode. It retains its prior state in
software standby mode.
Name
Port 3 data direction register
Port 3 data register
Port 3 MOS pull-up control
register
Bit
Initial value
Read/Write
Modes 1, 2, and 3 (EXPE = 1)
The input/output direction specified by P3DDR is ignored, and pins automatically function as
data I/O pins.
After a reset, and in hardware standby mode or software standby mode, the data I/O pins go to
the high-impedance state.
Modes 2 and 3 (EXPE = 0)
The corresponding port 3 pins are output ports when P3DDR bits are set to 1, and input ports
when cleared to 0.
* Lower 16 bits of the address.
Register Configuration
Port 3 Registers
P37DDR
W
7
0
P36DDR
W
6
0
Abbreviation
P3DDR
P3DR
P3PCR
P35DDR
W
5
0
P34DDR
W
4
0
R/W
W
R/W
R/W
Rev. 4.00 Jun 06, 2006 page 209 of 1004
P33DDR
W
3
0
Initial Value
H'00
H'00
H'00
P32DDR
W
2
0
P31DDR
Section 8 I/O Ports
REJ09B0301-0400
W
1
0
Address *
H'FFB4
H'FFB6
H'FFAE
P30DDR
W
0
0