Port 1; Port 1 Data Direction Register (P1Ddr) - Renesas H8S/2437 Hardware Manual

7.2

Port 1

Port 1 is an 8-bit I/O port. Port 1 pins also function as address bus pins, address/data multiplex bus
pins, and PWM output pins. Pin functions change according to the operating mode.
Port 1 has the following registers.

• Port 1 data direction register (P1DDR)

• Port 1 data register (P1DR)
• Port 1 register (PORT1)
• Port 1 pull-up MOS control register (P1PCR)
7.2.1 Port 1 Data Direction Register (P1DDR)
The individual bits in P1DDR specify input or output for the pins of port 1. The read value is
undefined.
Bit Bit Name
7 P17DDR
6 P16DDR
5 P15DDR
4 P14DDR
3 P13DDR
2 P12DDR
1 P11DDR
0 P10DDR
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
The corresponding port 1 pins are address
outputs when P1DDR bits are set to 1, and input
ports when cleared to 0.
•
In multiplex extended mode (16-bit bus width)
Operation is not affected
•
In multiplex extended mode (8-bit bus width)
Operates as single-chip mode
•
In single-chip mode
The corresponding port 1 pins are output ports
or PWM outputs when the P1DDR bits are set
to 1, and input ports when cleared to 0.
Rev. 1.00, 09/03, page 139 of 704