Datasheet

Section 10 I/O Ports
Rev. 6.00 Mar. 18, 2010 Page 305 of 982
REJ09B0054-0600
Section 10 I/O Ports
Table 10.1 summarizes the port functions. The pins of each port also have other functions such as
input/output or interrupt input pins of on-chip peripheral modules.
Each I/O port includes a data direction register (DDR) that controls input/output, a data register
(DR) that stores output data, and a port register (PORT) used to read the pin states. The input-only
ports do not have DR and DDR registers.
Ports A to E have a built-in input pull-up MOS function and an input pull-up MOS control register
(PCR) to control the on/off state of input pull-up MOS respectively.
Ports 3 and A include an open-drain control register (ODR) that controls the on/off state of the
output buffer PMOS respectively.
All the I/O ports can drive a single TTL load and a 30-pF capacitive load.
The P35 and P34 pins on port 3 are NMOS push pull outputs.*
The IRQ pin is Schmitt-trigger input.
Note: * Supported only by the H8S/2258 Group, H8S/2239 Group, and H8S/2238 Group.