MC68HC12 Datasheet, PDF (204/478 Pages) Motorola, Inc – The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit

Oscillator
Similarly, if meeting a traditional NRM optimization criteria is important,
then the components determined by this method are acceptable if the
same components yield a maximum allowed ESR greater than the
maximum ESR of the crystal while maintaining the worst case Gain
Margin of 2. There is no guarantee that components chosen through
traditional NRM optimization techniques will yield acceptable results
across all expected variations.
13.4.2.4 Key Parameters
The following items are of critical importance to the operation of the
oscillator:
• EXTAL–XTAL capacitor value — The value of the component
plus external (board) parasitic in excess of 0.1pF between EXTAL
and XTAL.
• XTAL–VSS capacitor value — The value of the component plus
external (board) parasitic in excess of 1.0pF between XTAL and
VSS.
• Maximum Shunt Capacitance — The maximum value of the
resonator’s shunt capacitance (C0) plus the external (board)
parasitics in excess of 1pF from EXTAL to VSS.
• VDDPLL Setting — The Voltage applied to the VDDPLL pin
(Logic 1 means VDDPLL is tied to the same potential as VDD).
• Resonator Frequency — The frequency of oscillation of the
resonator.
• Maximum ESR — The maximum effective series resistance
(ESR) of the resonator. This figure must include any increases
due to ageing, power dissipation, temperature, process variation
or particle contamination.
Technical Data
204
Oscillator
MC68HC912DT128A — Rev 4.0
MOTOROLA