Datasheet

Section 9 I/O Ports
Rev.6.00 Mar. 18, 2009 Page 360 of 980
REJ09B0050-0600
9.6 Port 8
Port 8 is a 6-bit I/O port that also has other functions. The port 8 has the following registers.
• Port 8 data direction register (P8DDR)
• Port 8 data register (P8DR)
• Port 8 register (PORT8)
9.6.1 Port 8 Data Direction Register (P8DDR)
The individual bits of P8DDR specify input or output for the pins of port 8.
P8DDR cannot be read; if it is, an undefined value will be read.
Bit Bit Name Initial Value R/W Description
7, 6 — All 0 — Reserved
These bits are always read as 0 and cannot be
modified.
5 P85DDR 0 W
4 — 0 —
3 P83DDR 0 W
2 — 0 —
1 P81DDR 0 W
0 — 0 —
When a pin function is specified to a general
purpose I/O, setting bit 5, 3, or 1 makes the
corresponding port 1 pin an output pin, while
clearing this bit to 0 makes the pin an input pin.
Bits 4, 2, and 0 are reserved.