HD6413008F RENESAS [Renesas Technology Corp], HD6413008F Datasheet - Page 189

• Manufacturer Part Number: HD6413008F
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7.2.2
Table 7.2 summarizes the registers of port 4.
Table 7.2
Address*
H'EE003
H'FFFD3
H'EE03E
Note:
Port 4 Data Direction Register (P4DDR): P4DDR is an 8-bit write-only register that can select
input or output for each pin in port 4.
When all areas are designated as 8-bit-access areas by the bus controller's bus width control
register (ABWCR), selecting 8-bit bus mode, port 4 functions as an input/output port. In this case,
a pin in port 4 becomes an output port if the corresponding P4DDR bit is set to 1, and an input
port if this bit is cleared to 0.
When at least one area is designated as a 16-bit-access area, selecting 16-bit bus mode, port 4
functions as part of the data bus, regardless of the P4DDR settings.
P4DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
P4DDR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting.
ABWCR and P4DDR are not initialized in software standby mode. Therefore, if a transition is
made to software standby mode while port 4 is functioning as an input/output port and a P4DDR
bit is set to 1, the corresponding pin maintains its output state.
Bit
Initial value
Read/Write
* Lower 20 bits of the address in advanced mode.
Register Descriptions
Port 4 Registers
Name
Port 4 data direction register
Port 4 data register
Port 4 input pull-up MOS control
register
P4 DDR
7
W
7
0
P4 DDR
6
W
6
0
P4 DDR
5
W
5
0
Port 4 data direction 7 to 0
These bits select input or output for port 4 pins
P4 DDR
4
W
4
0
Abbreviation
P4DDR
P4DR
P4PCR
Rev.4.00 Aug. 20, 2007 Page 145 of 638
P4 DDR
3
W
3
0
P4 DDR
2
W
2
0
R/W
W
R/W
R/W
P4 DDR
REJ09B0395-0400
1
W
1
0
Initial Value
H'00
H'00
H'00
7. I/O Ports
P4 DDR
0
W
0
0