HD6473032F16 Datasheet, PDF (289/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

9.5.2 Register Configuration
Table 9.6 summarizes the registers of port 4.
Table 9.6 Port 4 Registers
Address^* Name
H'FFC5
Port 4 data direction register
H'FFC7
Port 4 data register
H'FFDA
Port 4 input pull-up MOS control
register
Note: * Lower 16 bits of the address.
Section 9 I/O Ports
Abbreviation R/W
P4DDR
W
P4DR
R/W
P4PCR
R/W
Initial Value
H'00
H'00
H'00
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.
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
P4₇DDR P4₆DDR P4₅DDR P4₄DDR P4₃DDR P4₂DDR P4₁DDR P4₀DDR
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
Port 4 data direction 7 to 0
These bits select input or output for port 4 pins
• Modes 1 to 6 (Expanded Modes)
When all areas are designated as 8-bit-access areas, selecting 8-bit bus mode, port 4 functions
as a generic input/output port. 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.
• Mode 7 (Single-Chip Mode)
Port 4 functions as an input/output port. 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.
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.
Rev. 3.00 Mar 21, 2006 page 259 of 814
REJ09B0302-0300