Datasheet

Section 10 I/O Ports
Rev. 6.00 Mar. 18, 2010 Page 317 of 982
REJ09B0054-0600
10.2.4 Port 3 Open Drain Control Register (P3ODR)
P3ODR controls on/off state of the PMOS for port 3 pins.
Bit Bit Name Initial Value R/W Description
7 — Undefined — Reserved
These bits are always read as undefined value.
6 P36ODR 0 R/W
5 P35ODR 0 R/W
4 P34ODR 0 R/W
3 P33ODR 0 R/W
2 P32ODR 0 R/W
1 P31ODR 0 R/W
0 P30ODR 0 R/W
When each of P36ODR and P33ODR to P30ODR
bits is set to 1, the corresponding pins P36 and
P33 to P30 function as NMOS open drain outputs.
When cleared to 0, the corresponding pins
function as CMOS outputs. When each of
P35ODR and P34ODR bits is set to 1, the
corresponding pins P35 and P34 function as open
drain outputs. When they are cleared to 0, the
corresponding pins function as NMOS push pull
outputs.
*
Note: * When they are cleared to 0, the corresponding pins function as CMOS outputs in the
H8S/2237 Group and H8S/2227 Group.
10.2.5 Pin Functions
The port 3 pins also function as SCI I/O input pins, I2C bus interface* I/O pins, and as external
interrupt input pins.
As shown in figure 10.1, when the pins P35, P34, SCK1, SCL0, or SDA0 type open drain output
is used, a bus line is not affected even if the power supply for this LSI fails. Use (a) type open
drain output when using a bus line having a state in which the power is not supplied to this LSI.
Note: * The I
2
C bus interface is not available in the H8S/2237 Group and H8S/2227 Group.