Mansoor Mahfoud

9S12X Pierced Oscillator

Discussion created by Mansoor Mahfoud on Oct 21, 2007
Latest reply on Oct 24, 2007 by Mansoor Mahfoud
Can anyone please explain this?

Several 9S12X MCU datasheets (9S12XDP, 9S12XHZ and other) depict 2 types of Pierced Oscillator configurations possible for use in the 9S12X (and legacy 9S12) MCUs, the "Loop Controlled Pierced Oscillator" and the "Full Swing Pierced Oscillator". In the introduction overview of these datasheet, it is mentioned that the "Bias Resistor Rb" of the Pierced Oscillator is integrated in the MCU to relief the need of an external one. If so, how can we still differentiate between the "loop controlled" and the "Full Swing"? As far as I know, the architectural difference between the two types is actually the use of that "Bias Resistor". If it is already existing and connected internally, aren’t we strictly using the full swing oscillator in this case? Thank you guys,