Hi,
There seems to be an issue with startup on some types of crystals.
NXP put out an app note:
http://www.standardics.nxp.com/support/documents/microcontrollers/pdf/an10289.pdf
Hope it helps.
Jeff
--- In l..., "pyalpc936" wrote:
>
> Hi,
> I'm using a P89LPC936 with a 12MHz crystal (SMD case HC49/4H)
> The uC doesn't always start.
> It seems that oscillation level is too small (0.5V to 1.6V with 3.3V
> Vdd).
> Also it seems to work fine with a classic crystal (not SMD).
> The reason could be that classic crystal have serie resistance (about
> 10 ohms) much lower then SMD crystal (about 30 ohms). And the 89LPC936
> doesn't have enough gain to compensate the lost due du serial
> resistance.
> I don't find any information about crystal to use with LPC9XX
> microcontroler.
>
> Does anyone have informations or perhaps similar problems ?
>
> Thanks a lot
>