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7.3.3 Pin Functions in Each Mode
The pin functions of port 2 differ between mode 1, 3 (expanded mode with on-chip ROM
disabled), mode 5 (expanded mode with on-chip ROM enabled), mode 6, and 7 (single-chip
mode). The pin functions in each mode are described followings.
Modes 1 and 3: Address output can be selected for each pin in port 2. Figure 7-6 shows the pin
functions in modes 1 and 3.
Modes 5: Address output or generic input can be selected for each pin in port 2. A pin becomes an
address output pin if the corresponding P2DDR bit is set to 1, and a generic input pin if this bit is
cleared to 0. Following a reset, all pins are input pins. To use a pin for address output, its P2DDR
bit must be set to 1. Figure 7-7 shows the pin functions in modes 5.
142
Port 2
Figure 7-6 Pin Functions in Modes 1 and 3 (Port 2)
A
(output)
15
A
(output)
14
A
(output)
13
A
(output)
12
A
(output)
11
A
(output)
10
A (output)
9
A (output)
8
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