HD6417750RF240V Datasheet, PDF (173/606 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 9 I/O Ports
9.4 Port A
Port A is a 4-bit I/O port that also has other functions. Port A has the following registers. For
details on register addresses and register states during each processing, refer to appendix A, On-
Chip I/O Register.
• Port A data direction register (PADDR)
• Port A data register (PADR)
• Port A register (PORTA)
• Port A pull-up MOS control register (PAPCR)
• Port A open-drain control register (PAODR)
9.4.1 Port A Data Direction Register (PADDR)
PADDR is an 8-bit write-only register, the individual bits of which specify whether the pins of
port A are used for input or output. PADDR cannot be read; if it is, an undefined value will be
read.
Bit Bit Name
7—
6—
5—
4—
3 PA3DDR
2 PA2DDR
1 PA1DDR
0 PA0DDR
Initial Value R/W
Undefined —
Undefined —
Undefined —
Undefined —
0
W
0
W
0
W
0
W
Description
Reserved
When a pin is specified as a general purpose I/O
port, setting this bit to 1 makes the corresponding
port A pin an output pin. Clearing this bit to 0 makes
the pin an input pin.
Rev. 7.00 Sep. 11, 2009 Page 137 of 566
REJ09B0211-0700