Datasheet

Section 9 I/O Ports
Rev.6.00 Mar. 18, 2009 Page 327 of 980
REJ09B0050-0600
Mode 7
Port Description Mode 1
*
Mode 2
*
Mode 4
EXPE = 1 EXPE = 0
Input/
Output
Type
Port G General I/O port
also functioning
as bus control
I/Os
PG6/BREQ
PG5/BACK
PG4/CS4/BREQO
PG3/CS3/RAS3
PG2/CS2/RAS2
PG1/CS1
PG0/CS0
PG6/BREQ
PG5/BACK
PG4/CS4/
BREQO
PG3/CS3/
RAS3
PG2/CS2/
RAS2
PG1/CS1
PG0/CS0
PG6
PG5
PG4
PG3
PG2
PG1
PG0
Note: * Only modes 1 and 2 are available in the ROMless version.
9.1 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)
9.1.1 Port 1 Data Direction Register (P1DDR)
The individual bits of P1DDR specify input or output for the pins of port 1.
Bit Bit Name Initial Value R/W Description
7 P17DDR 0 W
6 P16DDR 0 W
5 P15DDR 0 W
4 P14DDR 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.
3 P13DDR 0 W
2 P12DDR 0 W
1 P11DDR 0 W
0 P10DDR 0 W