Datasheet
Section 8 I/O Ports 
Rev.7.00 Feb. 14, 2007  page 272 of 1108 
REJ09B0089-0700 
8.9.2 Register Configuration 
Table 8.15 shows the port D register configuration. 
Table 8.15  Port D Registers 
Name Abbreviation R/W Initial Value Address
*
Port D data direction register  PDDDR  W  H'00  H'FEBC 
Port D data register  PDDR  R/W  H'00  H'FF6C 
Port D register  PORTD  R  Undefined  H'FF5C 
Port D MOS pull-up control register  PDPCR  R/W  H'00  H'FF73 
Note: * Lower 16 bits of the address. 
Port D Data Direction Register (PDDDR) 
Bit : 7 6 5 4 3 2 1 0 
 PD7DDR PD6DDR PD5DDR PD4DDR PD3DDR PD2DDR PD1DDR PD0DDR 
Initial value : 0 0 0 0 0 0 0 0 
R/W : W W W W W W W W 
PDDDR is an 8-bit write-only register, the individual bits of which specify input or output for the 
pins of port D. PDDDR cannot be read; if it is, an undefined value will be read. 
PDDDR is initialized to H'00 by a reset, and in hardware standby mode. It retains its prior state in 
software standby mode. 
•  Modes 4 to 6
*
The input/output direction specification by PDDDR is ignored, and port D is automatically 
designated for data I/O. 
•  Mode 7
*
Setting PDDDR bits to 1 makes the corresponding port D pins output ports, while clearing the 
bits to 0 makes the pins input ports. 
Note: * Modes 6 and 7 are not available in the ROMless versions. 










