Datasheet

Section 9 I/O Ports
Page 268 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
9.10 Port E
Port E is an 8-bit I/O port that also has data bus (D7 to D0) I/O. 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)
9.10.1 Port E Data Direction Register (PEDDR)
The individual bits of PEDDR specify input or output for the pins of port E. Since this is a write-
only register, bit manipulation instructions should not be used to write to it. For details, see section
2.9.4, Accessing Registers Containing Write-Only Bits.
Bit Bit Name Initial Value R/W Description
7 PE7DDR 0 W
6 PE6DDR 0 W
5 PE5DDR 0 W
4 PE4DDR 0 W
3 PE3DDR 0 W
2 PE2DDR 0 W
1 PE1DDR 0 W
0 PE0DDR 0 W
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.
See section 6, Bus Controller, on 8-/16-bit bus mode.
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.