System Clock Oscillators; Main System Clock Oscillator - NEC mPD789426 Series User Manual

5.4 System Clock Oscillators

5.4.1 Main system clock oscillator

The main system clock oscillator is oscillated by the crystal or ceramic resonator (5.0 MHz TYP.) connected
across the X1 and X2 pins.
An external clock can also be input to the circuit. In this case, input the clock signal to the X1 pin, and input the
inverted signal to the X2 pin.
Figure 5-5 shows the external circuit of the main system clock oscillator.
(a) Crystal or ceramic oscillation
Crystal
or
ceramic resonator
108
CHAPTER 5 CLOCK GENERATOR
Figure 5-5. External Circuit of Main System Clock Oscillator
V
SS
X1
X2
User's Manual U15075EJ1V0UM00
(b) External clock
External
X1
clock
X2