UPD78F9234MC-5A4-A Datasheet, PDF (27/419 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 2 PIN FUNCTIONS
2.2.8 X1 and X2
These pins connect an oscillator to oscillate the X1 input clock.
X1 and X2 also function as the P121 and P122 pins, respectively. For settings of alternate function, refer to
CHAPTER 18 OPTION BYTE.
Supply an external clock to X1.
Caution The P121/X1 and P122/X2 pins are pulled down during reset.
2.2.9 AVREF
This is the A/D converter reference voltage input pin and the positive power supply pin of P20 to P23 and A/D
converter. When the A/D converter is not used, connect this pin to VDD.
2.2.10 AVSS
This is the A/D converter ground potential pin. Even when the A/D converter is not used, always use this pin with
the same potential as the VSS pin.
2.2.11 VDD
This is the positive power supply pin.
2.2.12 VSS
This is the ground pin.
User’s Manual U17446EJ5V0UD
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