Using MSP430F5659IPZ XT1 with 9HT10-32.768KDZF-T 32768 Hz crystal. Datasheet: www.txccrystal.com/.../9ht10.pdf This crystal advertises +/- 20 ppm accuracy with 12.5 pf load. My UCS XT1 settings are: XT1DRIVE 00 - lowest drive level XTS 0 - selects low frequency mode XT1BYPASS 0 - clock sourced internally XCAP 11 - selects 12 pF SMCLKOFF 0 XT1OFF 0 From the settings and from the device specific data sheet I believe that I have the required 12 pf load applied on the crystal. But it runs fast. I am prototyping units now and see more-or-less the same fast operation in 7 units. With crystals there are series and parallel operation circuits. I can't tell from MSP430 docs which the MSP430 implements. Can't tell from crystal data sheet if crystal is tuned in parallel mode. Anyone have any explanation for why the crystal runs fast or suggestion to slow it down? I know I can use the RTC to compensate, but -65 ppm is close to the limit of what the RTC can provide. I'd rather fix the problem with the crystal. Thanks! Mike
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