NEC uPD78056Y User Manual
Page 167
167
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
A
B
C
Pnm
V
DD
High
Current
X1