Register Descriptions; Table 7.16 Port 9 Registers - Hitachi H8/3062 Hardware Manual

7.10.2

Register Descriptions

Table 7.16 summarizes the registers of port 9.

Table 7.16 Port 9 Registers

Address *
Name
H'EE008 Port 9 data direction register
H'FFFD8 Port 9 data register
Note: * Lower 20 bits of the address in advanced mode
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
—
Initial value
Read/Write —
Reserved bits
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 7.17.
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.
196
7 6 5
— P9 DDR
5
1 1 0
— W
Abbreviation R/W
P9DDR W
P9DR R/W
4 3
P9 DDR P9 DDR P9 DDR
4 3
0 0
W W
Port 9 data direction 5 to 0
These bits select input or
output for port 9 pins
Initial Value
H'C0
H'C0
2 1 0
P9 DDR P9 DDR
2 1 0
0 0 0
W W W