UPD30102 Datasheet, PDF (54/701 Pages) NEC – 64/32-bit Microprocessor

CHAPTER 1 INTRODUCTION
Figure 1-9. External Circuit of Clock Oscillator
(a) Crystal oscillation
VR4102
GND
Note1
External
clock
(b) External clock
VR4102
Note1
Note2
Open Note2
Notes 1. CLKX1, RTCX1
2. CLKX2, RTCX2
Cautions 1. When using a clock oscillator, run wires in the area of this figure shown by broken lines,
according to the following rules, to avoid effects such as stray capacitance:
• Minimize the wire.
• Never cause the wires to cross other signal lines or run near a line carrying a large
varying current.
• Cause the grounding point of the capacitor of the oscillator circuit to have the same
potential as GND. Never connect the capacitor to a ground pattern carrying a large
current.
• Never extract a signal from the oscillator.
2. Take it into consideration that no load such as wiring capacity is applied to the CLKX2 or
RTCX2 pin when inputting an external clock.
Figure 1-10 shows examples of oscillator having bad connection.
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