Datasheet

Section 9 I/O Ports
Rev.6.00 Sep. 27, 2007 Page 353 of 1268
REJ09B0220-0600
9.2.2 Register Configuration
Table 9.2 shows the port 1 register configuration.
Table 9.2 Port 1 Registers
Name Abbreviation R/W Initial Value Address
*
Port 1 data direction register P1DDR W H'00 H'FEB0
Port 1 data register P1DR R/W H'00 H'FF60
Port 1 register PORT1 R Undefined H'FF50
Note: * Lower 16 bits of the address.
Port 1 Data Direction Register (P1DDR)
Bit : 7 6 5 4 3 2 1 0
P17DDR P16DDR P15DDR P14DDR P13DDR P12DDR P11DDR P10DDR
Initial value : 0 0 0 0 0 0 0 0
R/W : W W W W W W W W
P1DDR is an 8-bit write-only register, the individual bits of which specify input or output for the
pins of port 1. P1DDR cannot be read; if it is, an undefined value will be read.
Setting a P1DDR bit to 1 makes the corresponding port 1 pin an output pin, while clearing the bit
to 0 makes the pin an input pin.
P1DDR is initialized to H'00 by a reset, and in hardware standby mode. It retains its prior state in
software standby mode.