SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 128

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

6.1
The main oscillator of the C164CM is a power optimized Pierce oscillator providing an
inverter and a feedback element. Pins XTAL1 and XTAL2 connect the inverter to the
external crystal. The standard external oscillator circuitry (see
crystal, two low end capacitors, and a series resistor (Rx2) to limit the current through
the crystal. The additional LC combination is only required for 3
suppress oscillation in the fundamental mode. A test resistor (
inserted to measure the oscillation allowance of the oscillator circuitry.
Figure 6-2
The on-chip oscillator is optimized for an input frequency range of 4 to 16 MHz.
An external clock signal (e.g. from an external oscillator or from a master device) may
be fed to the input XTAL1. The Pierce oscillator then is not required to support the
oscillation itself, but is rather driven by the input signal. In this case, the input frequency
range may be 0 to 50 MHz (please note that the maximum applicable input frequency is
limited by the device’s maximum CPU frequency).
Note: Oscillator measurement within the final target system is recommended to
User’s Manual
determine the actual oscillation allowance for the oscillator-crystal system. The
measurement technique, examples for evaluated systems, and recommendations
are provided in a specific application note about oscillators (available via your
representative or WWW).
Oscillator
External Oscillator Circuitry
XTAL1
R
Q
6-3
Rx2
MCS04335
XTAL2
Figure
R
Q
rd
) may be temporarily
C164CM/C164SM
overtone crystals to
Clock Generation
6-2) comprises the
Derivatives
V1.0, 2002-02