UPD78F0138 NEC, UPD78F0138 Datasheet - Page 126

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

5.4 System Clock Oscillator
5.4.1 X1 oscillator
REGC pin is directly connected to V
input the clock signal to the X1 pin and input the inverse signal to the X2 pin.
5.4.2 Subsystem clock oscillator
and XT2 pins.
this case, input the clock signal to the XT1 pin and the inverse signal to the XT2 pin.
126
The X1 oscillator oscillates with a crystal resonator or ceramic resonator (Standard: 8.38 MHz, 10 MHz when
An external clock can be input to the X1 oscillator when the REGC pin is directly connected to V
Figure 5-8 shows examples of the external circuit of the X1 oscillator.
The subsystem clock oscillator oscillates with a crystal resonator (Standard: 32.768 kHz) connected to the XT1
External clocks can be input to the subsystem clock oscillator when the REGC pin is directly connected to V
Figure 5-9 shows examples of an external circuit of the subsystem clock oscillator.
Cautions are listed on the next page.
(a) Crystal, ceramic oscillation
Crystal resonator or
ceramic resonator
Figure 5-9. Examples of External Circuit of Subsystem Clock Oscillator
(a) Crystal oscillation
Figure 5-8. Examples of External Circuit of X1 Oscillator
32.768
DD
kHz
) connected to the X1 and X2 pins.
V
X1
X2
SS
CHAPTER 5 CLOCK GENERATOR
V
XT1
XT2
SS
User’s Manual U16228EJ2V0UD
External
clock
External
clock
(b) External clock
(b) External clock
X1
X2
XT1
XT2
DD
. In this case,
DD
. In