Datasheet
78K0/Kx2-L CHAPTER 5 CLOCK GENERATOR
R01UH0028EJ0400 Rev.4.00 213
Sep 27, 2010
5.4 System Clock Oscillator
5.4.1 X1 oscillator
The X1 oscillator oscillates with a crystal resonator or ceramic resonator (1 to 10 MHz) connected to the X1 and X2
pins.
An external clock can also be input. In this case, input the clock signal to the EXCLK pin.
Figure 5-13 shows an example of the external circuit of the X1 oscillator.
Figure 5-13. Example of External Circuit of X1 Oscillator
(a) Crystal or ceramic oscillation (b) External clock
X1
X2
V
SS
EXCLK
External clock
Cautions are listed on the next page.
5.4.2 XT1 oscillator
The XT1 oscillator
Note
oscillates with a crystal resonator (standard: 32.768 kHz) connected to the XT1 and XT2 pins.
An external clock can also be input. In this case, input the clock signal to the EXCLKS pin.
Figure 5-14 shows an example of the external circuit of the XT1 oscillator.
Note 78K0/KC2-L only
Figure 5-14. Example of External Circuit of XT1 Oscillator
(a) Crystal oscillation (b) External clock
XT2
V
SS
XT1
32.768
kHz
EXCLKS
External clock
Cautions are listed on the next page.