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Atmel AVR STK500 XT1 & XT2 pins?

Started by RajW March 10, 2004
Simple noobie question about the Atmel AVR STK500...

Can the XT1 and XT2 pins on PORTE\AUX used to supply a clock signal to
an external device (explanation below)?

As I am learning to program and interface the AVR's I have a 16550
UART on a separate experiment board and I see that the 16550 needs a
crystal or clock source on pins 16 and 17 (XIN and XOUT)... can the
XT1 and XT2 pins be used to supply the clock source or do I need a
separate crystal?

Thanks,
/*Raj*/
rajw@intelc64.net

/* To e-mail me remove the intel and change the net to us */
On Wed, 10 Mar 2004 11:39:37 -0500, RajW <rajw@intelc64.net> wrote:

> >Simple noobie question about the Atmel AVR STK500... > >Can the XT1 and XT2 pins on PORTE\AUX used to supply a clock signal to >an external device (explanation below)? > >As I am learning to program and interface the AVR's I have a 16550 >UART on a separate experiment board and I see that the 16550 needs a >crystal or clock source on pins 16 and 17 (XIN and XOUT)... can the >XT1 and XT2 pins be used to supply the clock source or do I need a >separate crystal?
You won't be able to use Port E's XT1 and XT2 "as if" they were a crystal and connect them to the 16550's XIN and XOUT. You may be able to pull the clock from XT1 and drive XIN with it, though. -- Rich Webb Norfolk, VA
On Thu, 11 Mar 2004 00:00:37 GMT, Rich Webb
<bbew.ar@mapson.nozirev.ten> wrote:
>You won't be able to use Port E's XT1 and XT2 "as if" they were a >crystal and connect them to the 16550's XIN and XOUT. You may be able to >pull the clock from XT1 and drive XIN with it, though.
Ahh... I think I see now. Pull the clock from (STK500)XT1 to (16550)XIN and then connect (16650)XOUT to ground through a resistor? /*Raj*/ P.S. I like how you antispammed your e-mail address. Dunno why I never thought of that one before.