Datasheet

Section 10 I/O Ports
Rev. 3.00 Mar 17, 2006 page 432 of 926
REJ09B0283-0300
Modes 3
*
1
, 7
Port Description
Modes 1
and 5
Modes 2
and 6
Mode 4
EXPE = 1 EXPE = 0
Input/
Output
Type
PH3/CS7/OE/CKE
*
2
/(IRQ7)PH3/CS7/OE/
CKE
*
2
/(IRQ7)
PH3/(IRQ7)
PH2/CS6/(IRQ6)PH2/CS6/(IRQ6)PH2/(IRQ6)
PH1/CS5/RAS5/SDRAMφ
*
2
PH1/CS5/RAS5/
SDRAMφ
*
2
PH1/SDRAMφ
*
2
Port
H
General I/O port
also functioning
as interrupt inputs
and bus control
I/Os
PH0/CS4/RAS4/WE
*
2
PH0/CS4/RAS4/
WE
*
2
PH0
Only PH2
and PH3
are
Schmitt-
triggered
inputs
when
used as
the IRQ
input
Notes: 1. Mode 3 is not supported in H8S/2678 Group.
2. These pins are not supported in H8S/2678 Group.
10.1 Port 1
Port 1 is an 8-bit I/O port that also has other functions. The port 1 has the following registers.
• Port 1 data direction register (P1DDR)
• Port 1 data register (P1DR)
• Port 1 register (PORT1)
10.1.1 Port 1 Data Direction Register (P1DDR)
The individual bits of P1DDR specify input or output for the pins of port 1.
P1DDR cannot be read; if it is, an undefined value will be read.
Bit Bit Name Initial Value R/W Description
7 P17DDR 0 W
6 P16DDR 0 W
5 P15DDR 0 W
4 P14DDR 0 W
3 P13DDR 0 W
2 P12DDR 0 W
1 P11DDR 0 W
0 P10DDR 0 W
When a pin function is specified to a general
purpose I/O, setting this bit to 1 makes the
corresponding port 1 pin an output pin, while
clearing this bit to 0 makes the pin an input pin.