UPD78F1502AGK-GAK-AX Datasheet, PDF (215/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 4 PORT FUNCTIONS
(2) Setting procedure when using I/O pins of simplified IIC10, IIC20 functions
<1> After reset release, the port mode is the input mode (Hi-Z).
<2> Externally pull up the pin to be used (on-chip pull-up resistor cannot be used).
In case of simplified IIC10: P14, P15
In case of simplified IIC20: P11, P10
<3> Set the output latch of the corresponding port to 1.
<4> Set the corresponding bit of the POM1 register to 1 to set the N-ch open drain output (VDD withstand
voltage) mode.
<5> Set the corresponding bit of the PM1 register to the output mode (data I/O is possible in the output mode).
At this time, the output data is high level, so the pin is in the Hi-Z state.
<6> Enable the operation of the serial array unit and set the mode to the simplified I²C mode.
R01UH0004EJ0501 Rev.5.01
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Jun 20, 2011