Port 3; Port 3 Data Direction Register (P3Ddr) - Renesas H8S/2437 Hardware Manual

7.4

Port 3

Port 3 is an 8-bit I/O port. Port 3 pins also function as bidirectional data bus and ExIRQ input pins.
Port 3 functions change according to the operating mode.
Port 3 has the following registers.

• Port 3 data direction register (P3DDR)

• Port 3 data register (P3DR)
• Port 3 register (PORT3)
• Port 3 pull-up MOS control register (P3PCR)
7.4.1 Port 3 Data Direction Register (P3DDR)
The individual bits in P3DDR specify input or output for the pins of port 3. The read value is
undefined.
Bit Bit Name
7 P37DDR
6 P36DDR
5 P35DDR
4 P34DDR
3 P33DDR
2 P32DDR
1 P31DDR
0 P30DDR
Initial Value R/W
0 W
0 W
0 W
0 W
0 W
0 W
0 W
0 W
Description
•
In normal extended mode
Operation is not affected.
•
In multiplex extended mode
Operates as single-chip mode
•
In single-chip mode
The corresponding port 3 pins are output ports
when the P3DDR bits are set to 1, and input
ports when cleared to 0.
Rev. 1.00, 09/03, page 155 of 704