Datasheet

Section 8 I/O Ports
Rev. 4.00 Jun 06, 2006 page 208 of 1004
REJ09B0301-0400
8.4 Port 3
8.4.1 Overview
Port 3 is an 8-bit I/O port. Port 3 pins also function as host data bus I/O pins (HDB7 to HDB0)
(H8S/2138 Group only), and as data bus I/O pins. Port 3 functions change according to the
operating mode. Port 3 has an on-chip MOS input pull-up function that can be controlled by
software.
Figure 8.9 shows the port 3 pin configuration.
P37/D7/HDB7
P36/D6/HDB6
P35/D5/HDB5
P34/D4/HDB4
P33/D3/HDB3
P32/D2/HDB2
P31/D1/HDB1
P30/D0/HDB0
Port 3
Port 3 pins
D7 (I/O)
D6 (I/O)
D5 (I/O)
D4 (I/O)
D3 (I/O)
D2 (I/O)
D1 (I/O)
D0 (I/O)
Pin functions in modes 1, 2 and 3 (EXPE = 1)
P37 (I/O)/HDB7 (I/O)
P36 (I/O)/HDB6 (I/O)
P35 (I/O)/HDB5 (I/O)
P34 (I/O)/HDB4 (I/O)
P33 (I/O)/HDB3 (I/O)
P32 (I/O)/HDB2 (I/O)
P31 (I/O)/HDB1 (I/O)
P30 (I/O)/HDB0 (I/O)
Pin functions in modes 2 and 3 (EXPE = 0)
Figure 8.9 Port 3 Pin Functions