Datasheet

CHAPTER 4 PORT FUNCTIONS

User’s Manual U18172EJ3V0UD

(4) Pull-up resistor option registers (PU2 to PU4)

These registers are used to specify whether an on-chip pull-up resistor is connected to P20 to P23, P32, P34,

P40 and P43. By setting PU2 to PU4, an on-chip pull-up resistor can be connected to the port pin

corresponding to the bit of PU2 to PU4.

PU2 to PU4 are set by using a 1-bit or 8-bit memory manipulation instruction.

Reset signal generation set these registers to 00H.

Figure 4-15. Format of Pull-up Resistor Option Register

Address: FF32H, After reset: 00H R/W

Symbol 7 6 5 4 3 2 1 0

PU2 0 0 0 0 PU23 PU22 PU21 PU20

Address: FF33H, After reset: 00H R/W

Symbol

7 6 5 4 3 2 1 0

PU3

0 0 0

PU34

Note

0 PU32 0 0

Address: FF34H, After reset: 00H R/W

Symbol 7 6 5 4 3 2 1 0

PU4 0 0 0 0 PU43 0 0 PU40

PUmn Selection of connection of on-chip pull-up resistor of Pmn (m = 2 to 4; n = 0 to 4)

0 Does not connect on-chip pull-up resistor

1 Connects on-chip pull-up resistor

Note

PD78F950x only

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