UPD78F9500MA-CAC-A Datasheet, PDF (82/342 Pages) Renesas Technology Corp – 8-Bit Single-Chip Microcontrollers

CHAPTER 5 CLOCK GENERATORS
Figure 5-7 shows examples of incorrect resonator connection.
Figure 5-7. Examples of Incorrect Resonator Connection (1/2)
(a) Too long wiring of connected circuit
(b) Crossed signal lines
PORT
VSS
X1
X2
VSS
X1
X2
(c) Wiring near high fluctuating current
VSS
X1
X2
(d) Current flowing through ground line of oscillator
(Potential at points A, B, and C fluctuates.)
VDD
VSS
X1
PORT
X2
A
B
C
High current
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User’s Manual U18172EJ3V0UD