Section 9 I/O Ports - Hitachi H8S/2628 Hardware Manual

Section 9 I/O Ports

Table 9.1 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 a DR or DDR register.
Ports A to D have built-in input pull-up MOS functions and input pull-up MOS control registers
(PCR) to control the on/off state of input pull-up MOS.
Ports A to C include an open-drain control register (ODR) that controls the on/off state of the
output buffer PMOS.
All the I/O ports can drive a single TTL load and a 30 pF capacitive load.
Rev. 1.0, 09/02, page 121 of 568