MC9S12NE64V1 Datasheet, PDF (178/554 Pages) Freescale Semiconductor, Inc – MC9S12NE64V1 Data Sheet

Chapter 5 Oscillator (OSCV2)
5.2.1 V_DDPLL and V_SSPLL — PLL Operating Voltage, PLL Ground
These pins provide the operating voltage (V_DDPLL) and ground (V_SSPLL) for the OSCV2 circuitry. This
allows the supply voltage to the OSCV2 to be independently bypassed.
5.2.2 EXTAL and XTAL — Clock/Crystal Source Pins
These pins provide the interface for either a crystal or a CMOS compatible clock to control the internal
clock generator circuitry. EXTAL is the external clock input or the input to the crystal oscillator amplifier.
XTAL is the output of the crystal oscillator amplifier. All the MCU internal system clocks are derived 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 Semiconductor recommends an evaluation of the application
board and chosen resonator or crystal by the resonator or crystal supplier.
The Crystal circuit is changed from standard.
The Colpitts circuit is not suited for overtone resonators and crystals.
EXTAL
MCU
CDC*
C1
Crystal or Ceramic
Resonator
XTAL
C2
V_SSPLL
* Due to the nature of a translated ground Colpitts oscillator
a DC voltage bias is applied to the crystal.
Please contact the crystal manufacturer for crystal DC bias
conditions and recommended capacitor value CDC.
Figure 5-1. Colpitts Oscillator Connections (XCLKS = 0)
NOTE
The Pierce circuit is not suited for overtone resonators and crystals without
a careful component selection.
MC9S12NE64 Data Sheet, Rev. 1.1
178
Freescale Semiconductor