Datasheet

Section 8 I/O Ports
Rev.7.00 Dec. 24, 2008 Page 255 of 698
REJ09B0074-0700
8.10 Port E
The port E is an 8-bit I/O port also functioning as data bus (D7 to D0) I/O pins. The port E has the
following registers.
• Port E data direction register (PEDDR)
• Port E data register (PEDR)
• Port E register (PORTE)
• Port E pull-up MOS control register (PEPCR)
8.10.1 Port E Data Direction Register (PEDDR)
PEDDR specifies input or output for the pins of the port E.
Since PEDDR is a write-only register, the bit manipulation instructions must not be used to write
PEDDR. 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
PE7DDR
PE6DDR
PE5DDR
PE4DDR
PE3DDR
PE2DDR
PE1DDR
PE0DDR
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
(H8S/2218 Group)
Modes 4 to 6:
When 8-bit bus mode is selected, port E functions as an
I/O port. Setting a PEDDR bit to 1 makes the
corresponding port E pin an output port, while clearing the
bit to 0 makes the pin an input port.
When 16-bit bus mode is selected, the input/output
direction settings in PEDDR are ignored, and port E pins
automatically function as data input/output pins.
For details on 8-bit/16-bit bus mode, refer to section 6,
Bus Controller.
Mode 7:
Setting a PEDDR bit to 1 makes the corresponding port E
pin an output port, while clearing the bit to 0 makes the
pin an input port.
(H8S/2212 Group)
Setting a PEDDR bit to 1 makes the corresponding port E
pin an output port, while clearing the bit to 0 makes the
pin an input port.