Based on this application note from Maxim Integrated in section "Resonance Mode":
"Crystals have two modes of resonance, parallel and series, and all crystals exhibit both resonance modes. The oscillator circuit is calibrated for one mode or the other, but not both."
I've been using this series crystal in PIC16F and NXP Cortex-M LPC1114 MCUs and since this is a series crystal I do not use small capacitors parallel to the crystal as usual seen in schematics.
My projects have always been working well and I haven't any problems so far. But after reading the aforementioned application note I started to worry about how I designed the oscillator part of the MCUs.
Also, when talking about "the oscillator circuit is callibrated for one mode or the other...", I couldn't find that information on the MCUs manuals or datasheets. The LPC1114 datasheet does not says anything about the resonant mode of its crystal oscillator circuit. However it clearly show in the drawings that a crystal with ceramic capacitors are expected to be connected in a parallel configuration, so I assumed that it's a parallel optimized oscillator circuit. And since I'm using a series crystal in a circuit that expects a parallel crystal I'm worried.
1 - Is it ok to use a series crystal in a parallel optimized oscillator? Can you affect the oscillation performance/accuracy doing that?
2 - How can I find out the type of expected resonant mode of a MCU if the datasheet does not inform that?