Datasheet

Section 10 I/O Ports
Rev. 6.00 Mar. 18, 2010 Page 318 of 982
REJ09B0054-0600
Output
0
(a) Open drain output type for
P34, P35, SCK1, SCL0, and SDA0 pins
NMOS Off
Output
(b) Open drain output type for
P33 to P30, SCL1, and SDA1 pins
PMOS Off
Input
1
Input
Figure 10.1 Types of Open Drain Outputs
The P34, P35, and SCK1 NMOS push-pull outputs will not output the Vcc level, regardless of the
load, even if set to the high output state. External pull-up resistors are required to output the Vcc
level.
Notes: 1. Note that the signal rise and fall times become longer when external pull-up resistors
are connected. If signals with long rise and fall times are input, use input circuits with
noise absorbing functions, such as Schmitt trigger circuits.
2. Implement external circuit countermeasures such as inserting level shifters if the device
is operated at high speeds.
3. See the output high-level voltage items in tables 27.2, 27.14, 27.27, and 27.39 on pages
34 to 35 for the output characteristics. Use values for the pull-up resistors such that the
allowable output current conditions in tables 27.3, 27.15, 27.28, and 27.40 are met.
* This is not present in the H8S/2227 Group and the H8S/2237 Group products.
The H8S/2227 Group and the H8S/2237 Group products do not have an IIC bus, and
the P34 and P35 pin outputs are CMOS outputs (when the P34ODR and P35ODR bits
for the pins are 0).
When using an emulator that includes either an H8S/2633 evaluation chip or an
H8S/2238 evaluation chip, these pins will be NMOS push-pull outputs. Therefore the
pin output characteristics will differ from those in the H8S/2227 Group and the
H8S/2237 Group products. If CMOS output characteristics are required in pins P34 and
P35, pull up the emulator P34 and P35 pins with an appropriate resistor.
• P36
The pin functions are switched as shown below according to the P36DDR bit condition.
P36DDR 0 1
Pin functions P36 input pin P36 output pin
*
Note: * When P36ODR is set to 1, functions as NMOS open drain output.