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Port 2 Input Pull-Up Control Register (P2PCR): P2PCR is an 8-bit readable/writable register
that controls the MOS input pull-up transistors in port 2.
Bit
7
P2 PCR
7
Initial value
0
Read/Write
R/W
When a P2DDR bit is cleared to 0 (selecting generic input), if the corresponding bit from
P2
PCR to P2
PCR is set to 1, the input pull-up transistor is turned on.
7
0
P2PCR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting.
7.3.3 Pin Functions in Each Mode
The pin functions of port 2 differ between modes 1 and 2 and mode 3. The pin functions in each
mode are described followings.
Modes 1 and 2: 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 7-5 shows the pin functions in modes 1 and 2.
Figure 7-5 Pin Functions in Modes 1 and 2 (Port 2)
6
5
P2 PCR
P2 PCR
P2 PCR
6
5
0
0
R/W
R/W
Port 2 input pull-up control 7 to 0
These bits control input pull-up
transistors built into port 2
When P2DDR = 1
A
(output)
15
A
(output)
14
A
(output)
13
A
(output)
12
Port 2
A
(output)
11
A
(output)
10
A (output)
9
A (output)
8
4
3
2
P2 PCR
P2 PCR
4
3
2
0
0
0
R/W
R/W
R/W
When P2DDR = 0
P2 (input)
7
P2 (input)
6
P2 (input)
5
P2 (input)
4
P2 (input)
3
P2 (input)
2
P2 (input)
1
P2 (input)
0
1
0
P2 PCR
P2 PCR
1
0
0
0
R/W
R/W
125
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