3069RF-ZTAT Datasheet, PDF (308/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

8.10.2 Register Descriptions
Table 8.16 summarizes the registers of port 9.
Table 8.16 Port 9 Registers
Address*
Name
Abbreviation R/W
H'EE008
Port 9 data direction register P9DDR
W
H'FFFD8
Port 9 data register
P9DR
R/W
Note: * Lower 20 bits of the address in advanced mode.
Initial Value
H'C0
H'C0
Port 9 Data Direction Register (P9DDR): P9DDR is an 8-bit write-only register that can select
input or output for each pin in port 9.
Bits 7 and 6 are reserved. They are fixed at 1, and cannot be modified.
Bit
7
—
Initial value
1
Read/Write
—
6
5
4
3
2
1
0
— P9₅DDR P9₄DDR P9₃DDR P9₂DDR P9₁DDR P9₀DDR
1
0
0
0
0
0
0
—
W
W
W
W
W
W
Reserved bits
Port 9 data direction 5 to 0
These bits select input or
output for port 9 pins
When port 9 functions as an input/output port, a pin in port 9 becomes an output port if the
corresponding P9DDR bit is set to 1, and an input port if this bit is cleared to 0. For the method of
selecting the pin functions, see table 8.17.
P9DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
P9DDR is initialized to H'C0 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting. Therefore, if a transition is made to software standby mode while
port 9 is functioning as an input/output port and a P9DDR bit is set to 1, the corresponding pin
maintains its output state.
Rev. 5.0, 09/04, page 286 of 978