
CHAPTER 12 PORTS
109
12.7.3 Specifying Pull-Up Resistor Incorporation Using Software
Pull-up resistor incorporation can be specified in 4-bit units using P0AGPU and P0BGPU (address 0CH) in the
register file.
Figure 12-3. Specifying Pull-Up Resistor Incorporation Using Software
Bit 3
Bit 2
Bit 1
Bit 0
P0BGPU
P0AGPU
R/W
0
0
0
0
0
P0AGPU
Function
Does not contain pull-up
resistor in port 0A.
1
Read/write
Initial value when reset
0
P0BGPU
Function
1
RF: 0CH
Read = R, write = W
0
0
Does not contain pull-up
resistor in port 0B.
Contains pull-up resistor in
port 0A.
Contains pull-up resistor in
port 0B.