Datasheet

Rev. 3.00, 03/04, page 183 of 830
8.1 Port 1
Port 1 is an 8-bit I/O port. Port 1 pins also function as an address bus, PWM output pins, and
address/data multiplex bus. Port 1 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 pull-up MOS control register (P1PCR)
8.1.1 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
3 P13DDR 0 W
2 P12DDR 0 W
1 P11DDR 0 W
0 P10DDR 0 W
In normal extended mode (ADMXE = 0):
The corresponding port 1 pins are address output
when P1DDR bits are set to 1, and input ports when
cleared to 0.
In address/data multiplex extended mode (ADMXE =
1):
When the bus width is 16 bits, lower 8 bits of
address/data multiplex bus. When the bus width is 8
bits, this register is used in the same way as in 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.