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CHAPTER 4 PORT FUNCTIONS
Preliminary User’s Manual U16035EJ1V0UM
(2) Pull-up resistor option registers (PU0, PU2 to PU5, PU7)
These registers are used to set whether to use an on-chip pull-up resistor at each port or not. By setting PU0,
PU2 to PU5, and PU7, the on-chip pull-up resistors of the port pins corresponding to the bits in PU0, PU2 to PU5,
and PU7 can be used.
PU0, PU2 to PU5, and PU7 are independently set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets registers to 00H.
Cautions 1. The P10 to P13 pins do not incorporate a pull-up resistor.
2. When PUm is set to 1, the on-chip pull-up resistor is connected irrespective of the input/
output mode. When using in output mode, therefore, set the bit of PUm to 0 (m = 0, 2 to
5, 7).