Port 9; Port 9 Data Direction Register (P9Ddr) - Renesas H8S/2158 User Manual

Section 9 I/O Ports
9.9

Port 9

Port 9 is an 8-bit I/O port. However note that pin P96 cannot be used as a general output port. Port
9 pins also function as the bus control I/O pins, CompactFlash control I/O pins, the system clock
output pin, and the external subclock input pin. Pin functions are switched depending on the
operating mode. Port 9 has the following registers.

• Port 9 data direction register (P9DDR)

• Port 9 data register (P9DR)
9.9.1 Port 9 Data Direction Register (P9DDR)
The individual bits of P9DDR specify input or output for the pins of port 9.
Bit Bit Name
7 P97DDR
6 P96DDR
5 P95DDR
4 P94DDR
3 P93DDR
2 P92DDR
1 P91DDR
0 P90DDR
Rev. 3.00 Jan 25, 2006 page 250 of 872
REJ09B0286-0300
Initial Value R/W
0 W
0 W
0 W
0 W
0 W
0 W
0 W
0 W
Description
If port 9 pins are specified for use as the general
I/O port, the corresponding port 9 pins are output
ports when the P9DDR bits are set to 1, and input
ports when cleared to 0.
When this bit is set to 1, the corresponding port 9
pin is the system clock output pin (φ), and as a
general input port when cleared to 0.
If port 9 pins are specified for use as the general
I/O port, the corresponding port 9 pins are output
ports when the P9DDR bits are set to 1, and input
ports when cleared to 0.