NEC PD750008 User Manual
Page 110
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µPD750008 USER'S MANUAL
Any line carrying a high pulsating current must be kept away as far as possible.
• The grounding point of the capacitor of the oscillator must have the same
potential as that of V
SS
. It must not be grounded to a grounding pattern carry
ing a high current.
• No signal must be taken directly from the resonator.
The subsystem clock oscillator has low amplification to minimize current con-
sumption. For this reason, more malfunctions can occur due to noise than the
main system clock oscillator. So pay special attention to wiring when using the
subsystem clock.
Figure 5-16 gives examples of oscillator connections which should be avoided.
Figure 5-16. Examples of Oscillator Connections Which Should Be Avoided (1/2)
(a) The wiring is too long.
(b) The signal lines cross.
Remark When wiring the subsystem clock, read X1 and X2 as XT1 and XT2 respectively. In this case,
a resistor must be added to XT2 in series.
µPD750008
V
SS
X1
X2
µPD750008
V
SS
X1
X2
PORTn
(n = 0 to 8)