CHAPTER 5 CLOCK GENERATOR
User’s Manual U16899EJ2V0UD
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5.4 System Clock Oscillator
5.4.1 High-speed system clock oscillator
The high-speed system clock oscillator oscillates with a crystal resonator or ceramic resonator connected to the X1
and X2 pins.
An external clock can be input to the high-speed system clock oscillator. In this case, input the clock signal to the
X1 pin and input the inverse signal to the X2 pin.
Figure 5-8 shows examples of the external circuit of the high-speed system clock oscillator.
Figure 5-8. Examples of External Circuit of High-Speed System Clock Oscillator
(a) Crystal, ceramic oscillation
(b) External clock
V
SS
X1
X2
Crystal resonator or
ceramic resonator
External
clock
X1
X2
Cautions are listed on the next page.
5.4.2 Subsystem clock oscillator
The subsystem clock oscillator oscillates with a crystal resonator (Standard: 32.768 kHz) connected to the XT1
and XT2 pins.
External clocks can be input to the subsystem clock oscillator. In this case, input the clock signal to the XT1 pin
and the inverse signal to the XT2 pin.
Figure 5-9 shows examples of an external circuit of the subsystem clock oscillator.
Figure 5-9. Examples of External Circuit of Subsystem Clock Oscillator
(a) Crystal oscillation
(b) External clock
XT2
V
SS
XT1
32.768
kHz
XT1
XT2
External
clock
Cautions are listed on the next page.