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CHAPTER 7 CLOCK GENERATOR
IC X1 X2
IC X2 X1
High
Current
Figure 7-8. Examples of Incorrect Oscillator Connection (2/2)
(c) Changing high current is too near a (d) Current flows through the grounding line
signal conductor of the oscillator (potential at points A, B,
and C fluctuate)
(e) Signals are fetched
Remark When using a subsystem clock, replace X1 and X2 with XT1 and XT2, respectively. Also, insert resistors
in series on the XT2 side.
Cautions 2. In Figure 7-8 (f), XT2 and X1 are wired in parallel. Thus, the cross-talk noise of X1 may
increase with XT2, resulting in malfunctioning. To prevent that from occurring, it is
recommended to wire XT2 and X1 so that they are not in parallel, and to correct the IC pin
between XT2 and X1 directly to V
SS
.
IC X2
AB C
Pnm
VDD
High
Current
X1