H8SLASH3021 datasheet(187/712 Pages) RENESAS

187 / 712 page

7. I/O Ports

Rev.2.00 Mar. 22, 2007 Page 163 of 684

REJ09B0352-0200

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.

Bit

Initial value

Read/Write

—

P9 DDR

Reserved bits

Port 9 data direction 5 to 0

These bits select input or

output for port 9 pins

A pin in port 9 becomes an output pin if the corresponding P9DDR bit is set to 1, and an input pin

if this bit is cleared to 0.

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. If a P9DDR bit is set to 1, the corresponding pin maintains its output

state in software standby mode.

Port 9 Data Register (P9DR): P9DR is an 8-bit readable/writable register that stores output data

for pins P9

5 to P90.

Bit

Initial value

Read/Write

—

R/W

Reserved bits

Port 9 data 5 to 0

These bits store data

for port 9 pins

When a bit in P9DDR is set to 1, if port 9 is read the value of the corresponding P9DR bit is

returned. When a bit in P9DDR is cleared to 0, if port 9 is read the corresponding pin level is read.

Bits 7 and 6 are reserved. They cannot be modified and are always read as 1.

P9DR is initialized to H'C0 by a reset and in hardware standby mode. In software standby mode it

retains its previous setting.

H8/3021 Datasheet(PDF) 187 Page - Renesas Technology Corp