Re: Oscilator Boot problem
Bruce Boyes <[email protected]>
| Newsgroups | gmane.comp.hardware.microcontrollers.tini |
|---|---|
| Message-ID | <[email protected]> |
At 11:23 PM 2/10/2004 -0200, william wrote: >Hello, > >We developed a custom board based in the reference design. > >We have this problem: when we power-on the board the oscillator of the cpu >starts to work, but it stops after 200 ms aprox. We tried different >crystals, with differents values of capacitors, without any result. Are you using the correct crystal and caps? 8051s need parallel-resonant, fundamental-mode crystals, and the value of the caps varies a bit depending on the crystal vendor. The capacitive loading includes board capacitance and capacitance of the controller itself, then you add whatever additional is needed to comply with the manufacturer's specifications. It's my guess that you are either 1) using the wrong type of crystal, or 2) the wrong circuit for the crystal or 3) something is really wrong in the board layout. Otherwise, assuming the controller chip is OK and is being properly powered (something else to check), it has to work. Bruce _______________________________________________ TINI mailing list TINI-6tN4nzCoH/[email protected] To UNSUBSCRIBE, edit your profile, or see list archives: http://lists.dalsemi.com/mailman/listinfo/tini