HD64F2145 Datasheet, PDF (203/829 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

8.3 Port 2
Port 2 is an 8-bit I/O port. Port 2 pins also function as address bus output function, 8-bit PWM
output pins, and the timer connection output pin. Port 2 functions change according to the
operating mode. Port 2 has an on-chip input pull-up MOS function that can be controlled by
software. Port 2 has the following registers.
• Port 2 data direction register (P2DDR)
• Port 2 data register (P2DR)
• Port 2 pull-up MOS control register (P2PCR)
8.3.1 Port 2 Data Direction Register (P2DDR)
P2DDR specifies input or output for the pins of port 2 on a bit-by-bit basis.
Bit Bit Name Initial Value R/W
7
P27DDR 0
W
6
P26DDR 0
W
5
P25DDR 0
W
4
P24DDR 0
W
3
P23DDR 0
W
2
P22DDR 0
W
1
P21DDR 0
W
0
P20DDR 0
W
Description
In Mode 1:
The corresponding port 2 pins are address outputs,
regardless of the P2DDR setting.
Modes 2 and 3 (EXPE = 1):
The corresponding port 2 pins are address outputs
or PWM outputs when P2DDR bits are set to 1,
and input ports when cleared to 0. P27 to P24 are
switched from address outputs to output ports by
setting the IOSE bit to 1.
P27 can be used as an on-chip peripheral module
output pin regardless of the P27DDR setting, but to
ensure normal access to external space, P27
should not be set as an on-chip peripheral module
output pin when port 2 pins are used as address
output pins.
Modes 2 and 3 (EXPE = 0):
The corresponding port 2 pins are output ports or
PWM outputs when P2DDR bits are set to 1, and
input ports when cleared to 0.
P27 can be used as an on-chip peripheral module
output pin regardless of the P27DDR setting.
Rev. 2.0, 08/02, page 163 of 788