User's Manual

CONTROL
43
3. CONTROL
3.1 Oscillators: XTAL1
XTAL2
An oscillator is formed by connecting a crystal or ceramic resonator between the XTAL1 and
XTAL2 pins of the MSM80C154S/MSM83C154S devices.
If an external clock is applied to XTAL1, the input should be at 50% duty and C-MOS level.
IDLE MODE
PD & HPD MODE
CPU CONTROL CLOCK
TIMER, S I/O & INTERRUPT
1MΩ
XTAL1
XTAL2
XTAL
C
C
*
*
MSM80C154S/MSM83C154S
* The capacity of the compensating capacitor depends on the crystal resonator.
* The XTAL1·2 frequency depends on VCC.
Figure 3-1 Crystal resonator connection diagram