Port B; Port B Data Direction Register (Pbddr) - Renesas H8S/2368 Series Hardware Manual

9.9

Port B

Port B is an 8-bit I/O port that also has other functions. The port B has the following registers.

• Port B data direction register (PBDDR)

• Port B data register (PBDR)
• Port B register (PORTB)
• Port B MOS pull-up control register (PBPCR)
9.9.1 Port B Data Direction Register (PBDDR)
The individual bits of PBDDR specify input or output for the pins of port B.
PBDDR cannot be read; if it is, an undefined value will be read.
Bit Bit Name Initial Value
7 PB7DDR 0
6 PB6DDR 0
5 PB5DDR 0
4 PB4DDR 0
3 PB3DDR 0
2 PB2DDR 0
1 PB1DDR 0
0 PB0DDR 0
Rev. 2.00, 05/03, page 348 of 820
R/W Description
•
W
Modes 1 and 2
Port B pins are address outputs regardless of the
W
PBDDR settings.
W
•
Modes 4 and 7 (when EXPE = 1)
W
Setting a PBDDR bit to 1 makes the corresponding
W
port B pin an address output, while clearing the bit to
W
0 makes the pin an input port.
•
W
Mode 7 (when EXPE = 0)
Port B is an I/O port, and its pin functions can be
W
switched with PBDDR.