Datasheet

Section 8 I/O Ports
Rev.7.00 Dec. 24, 2008 Page 250 of 698
REJ09B0074-0700
8.9 Port D (H8S/2218 Group Only)
The port D is an 8-bit I/O port also functioning as data bus (D15 to D8) I/O pins. The port D has
the following registers.
• Port D data direction register (PDDDR)
• Port D data register (PDDR)
• Port D register (PORTD)
• Port D pull-up MOS control register (PDPCR)
8.9.1 Port D Data Direction Register (PDDDR)
PDDDR specifies input or output for the pins of the port D.
Since PDDDR is a write-only register, the bit manipulation instructions must not be used to write
PDDDR. For details, see section 2.9.4, Accessing Registers Containing Write-Only Bits.
Bit Bit Name Initial Value R/W Description
7
6
5
4
3
2
1
0
PD7DDR
PD6DDR
PD5DDR
PD4DDR
PD3DDR
PD2DDR
PD1DDR
PD0DDR
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
Modes 4 to 6:
Port D pins automatically function as data input/output
pins.
Mode 7:
Setting a PDDDR bit to 1 makes the corresponding port D
pin an output port, while clearing the bit to 0 makes the
pin an input port.