UPD75238GJ NEC [NEC], UPD75238GJ Datasheet - Page 54

• Manufacturer Part Number: UPD75238GJ
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC [NEC]

54
(5) System clock oscillator
The main system clock oscillator operates with a crystal (6.0 MHz standard) or ceramic resonator
connected to the X1 and X2 pins.
An external clock can also be input.
Caution When an external clock is used, the STOP mode cannot be set. This is because the X1 pin is
(a) Crystal/ceramic oscillation
connected to V
Crystal
oscillator
or ceramic
oscillator
Fig. 4-17 External Circuitry for the Main System Clock Oscillator
X1
X2
SS
in the STOP mode.
PD75238
External
clock
(b) External clock
X1
X2
PD75238
PD75238