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HD6473032F16 Datasheet, PDF (313/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
Section 9 I/O Ports
9.11.2 Register Configuration
Table 9.18 summarizes the registers of port A.
Table 9.18 Port A Registers
Address* Name
H'FFD1
Port A data direction
register
H'FFD3
Port A data register
Note: * Lower 16 bits of the address.
Abbreviation R/W
PADDR
W
PADR
R/W
Initial Value
Modes
Modes
1, 2, 5 and 7 3, 4, and 6
H'00
H'80
H'00
H'00
Port A Data Direction Register (PADDR)
PADDR is an 8-bit write-only register that can select input or output for each pin in port A. When
pins are used for TPC output, the corresponding PADDR bits must also be set.
Bit
7
6
5
4
3
2
1
0
PA7 DDR PA6 DDR PA5 DDR PA4 DDR PA3 DDR PA2 DDR PA1 DDR PA0 DDR
Modes
3, 4,
Initial value
1
0
0
0
0
0
0
0
and 6 Read/Write —
W
W
W
W
W
W
W
Modes Initial value 0
0
0
0
0
0
0
0
1, 2, 5,
and 7 Read/Write W
W
W
W
W
W
W
W
Port A data direction 7 to 0
These bits select input or output for port A pins
A pin in port A becomes an output pin if the corresponding PADDR bit is set to 1, and an input
pin if this bit is cleared to 0. In modes 3, 4, and 6, PA7DDR is fixed at 1 and PA7 functions as an
address output pin.
PADDR is a write-only register. Its value cannot be read. All bits return 1 when read.
PADDR is initialized to H'00 by a reset and in hardware standby mode in modes 1, 2, 5, and 7.
It is initialized to H'80 by a reset and in hardware standby mode in modes 3, 4, and 6. In software
standby mode it retains its previous setting. If a PADDR bit is set to 1, the corresponding pin
maintains its output state in software standby mode.
Rev. 3.00 Mar 21, 2006 page 283 of 814
REJ09B0302-0300