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9 port 9, 1 port 9 data direction register (p9ddr), 2 port 9 data register (p9dr) – Renesas H8S/2111B User Manual

Page 156

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Rev. 1.00, 05/04, page 122 of 544

7.9 Port

9

Port 9 is an 8-bit I/O port. Port 9 pins also function as the interrupt input pins, IIC_0 I/O pin,
subclock input pin, and system clock (

φ) output pin. P97 is an NMOS push-pull output. SDA0 is

an NMOS open-drain output, and has direct bus drive capability. Port 9 has the following
registers.

• Port 9 data direction register (P9DDR)
• Port 9 data register (P9DR)

7.9.1

Port 9 Data Direction Register (P9DDR)

P9DDR specifies input or output for the pins of port 9 on a bit-by-bit basis.

Bit Bit

Name

Initial
Value

R/W Description

7 P97DDR

0 W

6 P96DDR

0 W

5 P95DDR

0 W

4 P94DDR

0 W

3 P93DDR

0 W

2 P92DDR

0 W

1 P91DDR

0 W

0 P90DDR

0 W

When the corresponding P9DDR bits are set to 1, pin
P96 functions as the

φ output pin and pins P97 and

P95 to P90 become output ports. When P9DDR bits
are cleared to 0, the corresponding pins become input
ports.

7.9.2

Port 9 Data Register (P9DR)

P9DR stores output data for the port 9 pins.

Bit Bit

Name

Initial
Value R/W

Description

7 P97DR

0

R/W

6 P96DR

Undefined* R

5 P95DR

0

R/W

4 P94DR

0

R/W

3 P93DR

0

R/W

2 P92DR

0

R/W

1 P91DR

0

R/W

0 P90DR

0

R/W

With the exception of P96, if a port 9 read is performed
while P9DDR bits are set to 1, the P9DR values are
read directly, regardless of the actual pin states. If a
port 9 read is performed while P9DDR bits are cleared
to 0, the pin states are read.

For P96, the pin state is always read.

Note: * The initial value of bit 6 is determined according to the P96 pin state.

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