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6.1.5 Connecting pull-up resistor
Each port pin of the µ PD754244 can be connected to a pull-up resistor. Some pins can be connected to a pull-
up resistor via software and others can be connected by a mask option.
Table 6-4 shows how to specify the connection of the pull-up resistor to each port pin. The pull-up resistor is
connected via software in the format shown in Figure 6-11.
The pull-up resistor can be connected only to the pins of ports 3, 6, and 8 in the input mode. When the pins are
set to the output mode, the pull-up resistor cannot be connected regardless of the setting of POGA and POGB.
Port (Pin Name)
Port 3 (P30-P33)
Port 6 (P60-P63)
Port 7 (P70-P73)
Port 8 (P80-P83)
Figure 6-11. Format of Pull-up Resistor Specification Register
Pull-up resistor specification register group A
Address
7
FDCH
–
Pull-up resistor specification register group B
Address
FDEH
100
CHAPTER 6 PERIPHERAL HARDWARE FUNCTION
Table 6-4. Specifying Connection of Pull-up Resistor
Specifying Connection of Pull-up Resistor
Connection of pull-up resistor specified in 4-bit
units via software
Connection of pull-up resistor specified in 1-bit
units by mask option
Connection of pull-up resistor specified in 1-bit
units via software
0
Pull-up resistor not connected
1
Pull-up resistor connected
6
5
4
3
PO6
–
–
PO3
7
6
5
4
–
–
–
–
User's Manual U10676EJ3V0UM
Specification
2
1
0
Symbol
–
–
–
POGA
3
2
1
0
–
–
–
PO8
Specified Bit
POGA.3
POGA.6
—
POGB.0
Port 3 (P30 to P33)
Port 6 (P60 to P63)
Symbol
POGB
Port 8 (P80)
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