UPD78320GJ-5BJ NEC, UPD78320GJ-5BJ Datasheet - Page 34

• Manufacturer Part Number: UPD78320GJ-5BJ
• Description: 16/8-BIT SINGLE-CHIP MICROCONTROLLER
• Manufacturer: NEC

34
Cautions 1. When the system clock oscillator is used, the following points should be noted concerning wiring
(a) Crystal oscillator
(b) External clock
(i) When the inverted phase of an external clock
External
Clock
to be input to the X1 pin is input to the X2 pin
2. When an external clock is input to the X1 pin and the X2 pin is left open, ensure that no loads such
within broken lines shown in Figure 3-2, in order to prevent the effects of wiring capacitance, etc.
• Keep the wiring as short as possible.
• Do not cross any other signal lines, and keep clear of lines in which a high fluctuating current flows.
• Ensure that oscillator capacitor connection points are always at the same potential as V
• Do not take a signal from the oscillator.
as wiring capacitance are connected to the X2 pin.
Do not ground in a ground pattern in which a high current flows.
Figure 3-2. Externally-Mounted System Clock Oscillator
X1
X2
X2
X1
V
PD78322
SS
PD78322
External
Clock
(ii) When X2 pin is left open
Open
PD78320, 78322
X1
X2
PD78322
SS
.