Datasheet

Section 8 I/O Ports
Rev. 4.00 Sep 27, 2006 page 209 of 1130
REJ09B0327-0400
Section 8 I/O Ports
8.1 Overview
This LSI have ten I/O ports (ports 1 to 6, 8, 9, A, and B), and one input-only port (port 7).
Tables 8.1 to 8.3 summarize the port functions. The pins of each port also have other functions.
Each port includes a data direction register (DDR) that controls input/output (not provided for the
input-only port) and data registers (DR, ODR) that store output data.
Ports 1 to 3, 6, A, and B have a built-in MOS input pull-up function. For ports A and B, the on/off
status of the MOS input pull-up is controlled by DDR and ODR. Ports 1 to 3 and 6 have a MOS
input pull-up control register (PCR), in addition to DDR and DR, to control the on/off status of the
MOS input pull-ups.
Ports 1 to 6, 8, 9, A, and B can drive a single TTL load and 30 pF capacitive load. All the I/O
ports can drive a Darlington transistor when in output mode. Ports 1, 2, and 3 can drive an LED
(10 mA sink current).
PA4 to PA7 in port A have bus buffer drive capability. In the H8S/2148 Group and H8S/2147N,
P52 in port 5 and P97 in port 9 are NMOS push-pull outputs.
Note that the H8S/2144 Group and H8S/2147N have subset specifications that do not include
some supporting modules. For differences in pin functions, see table 8.1, H8S/2148 Group Port
Functions, table 8.2, H8S/2147N Port Functions, and table 8.3, H8S/2144 Group Port Functions.