Datasheet

Section 8 I/O Ports
Rev.7.00 Dec. 24, 2008 Page 216 of 698
REJ09B0074-0700
8.1 Port 1
In the H8S/2218 Group, the port 1 is an 8-bit I/O port also functioning as address bus pins, TPU
I/O pins, and external interrupt input pins. In the H8S/2212 Group, the port 1 is an 8-bit I/O port
also functioning as TPU I/O pins and external interrupt input pins. The port 1 has the following
registers.
• Port 1 data direction register (P1DDR)
• Port 1 data register (P1DR)
• Port 1 register (PORT1)
8.1.1 Port 1 Data Direction Register (P1DDR)
P1DDR specifies input or output for the pins of the port 1.
Since P1DDR is a write-only register, the bit manipulation instructions must not be used to write
P1DDR. For details, see section 2.9.4, Accessing Registers Containing Write-Only Bits.
Bit Bit Name Initial Value R/W Description
7
6
5
4
3
2
1
0
P17DDR
P16DDR
P15DDR
P14DDR
P13DDR
P12DDR
P11DDR
P10DDR
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
(H8S/2218 Group)
Modes 4 to 6:
If address output is enabled by the setting of bits AE3 to
AE0 in PFCR, pins P13 to P10 are address outputs. Pins
P17 to P14, and pins P13 to P10 when address output is
disabled, are output ports when the corresponding
P1DDR bits are set to 1, and input ports when the
corresponding P1DDR bits are cleared to 0.
Mode 7:
Setting a P1DDR bit to 1 makes the corresponding port 1
pin an output port, while clearing the bit to 0 makes the
pin an input port.
(H8S/2212 Group)
Setting a P1DDR bit to 1 makes the corresponding port 1
pin an output port, while clearing the bit to 0 makes the
pin an input port.