Datasheet

Chapter 12 Pierce Oscillator (S12XOSCLCPV2)
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor 501
from the EXTAL input frequency. In full stop mode (PSTP = 0), the EXTAL pin is pulled down by an
internal resistor of typical 200 kΩ.
NOTE
Freescale recommends an evaluation of the application board and chosen
resonator or crystal by the resonator or crystal supplier.
Loop controlled circuit is not suited for overtone resonators and crystals.
Figure 12-2. Loop Controlled Pierce Oscillator Connections (LCP mode selected)
NOTE
Full swing Pierce circuit is not suited for overtone resonators and crystals
without a careful component selection.
Figure 12-3. Full Swing Pierce Oscillator Connections (FSP mode selected)
Figure 12-4. External Clock Connections (FSP mode selected)
MCU
EXTAL
XTAL
V
SSPLL
Crystal or
Ceramic Resonator
C2
C1
* R
s
can be zero (shorted) when use with higher frequency crystals.
Refer to manufacturer’s data.
MCU
EXTAL
XTAL
RS*
RB
V
SSPLL
Crystal or
Ceramic Resonator
C2
C1
MCU
EXTAL
XTAL
Not Connected
CMOS Compatible
External Oscillator
(V
DDPLL
Level)