Chapter 6 Pierce Oscillator (S12XOSCLCPV1)
MC9S12XDP512 Data Sheet, Rev. 2.11
Freescale Semiconductor 313
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 6-2. Loop Controlled Pierce Oscillator Connections (XCLKS = 0)
NOTE
Full swing Pierce circuit is not suited for overtone resonators and crystals
without a careful component selection.
Figure 6-3. Full Swing Pierce Oscillator Connections (XCLKS = 1)
Figure 6-4. External Clock Connections (XCLKS = 1)
MCU
EXTAL
XTAL
VSSPLL
Crystal or
Ceramic Resonator
C2
C1
* Rs can be zero (shorted) when use with higher frequency crystals.
Refer to manufacturer’s data.
MCU
EXTAL
XTAL RS*
RB
VSSPLL
Crystal or
Ceramic Resonator
C2
C1
MCU
EXTAL
XTAL Not Connected
CMOS Compatible
External Oscillator
(VDDPLL Level)