Re: [avr-chat] Using 32.768Khz crystal for timer 2

[Neil Davey]

Hi Ori,
Ok, so you need to connect the 32kHz crystal to the TOSC1 and TOSC2 
pins, not the XTAL pins..

Regards
Neil Davey

address@hidden wrote:
> Thank you for your answer,
>
> I have enabled global interrupt flag (I did get interrupts from the 
> serial port)
> I would like to use the crystal only for the timer.
> the CPU itself is running on the internal oscillator (default).
>
> --
> Ori Idan
>
>
> On Wed, Apr 16, 2008 at 10:43 AM, Neil Davey <address@hidden 
> <mailto:address@hidden>> wrote:
>
>     Hi Ori,
>
>
>     address@hidden
>     <mailto:address@hidden> wrote:
>
>         I have a simple system with 32.768Khz crystal connected to
>         XTAL1 and XTAL2
>         Do I need a special operation to enable it?
>
>         I did the following initializations in order to get a 1sec
>         interrupt:
>
>            TCCR2B = 0x05;            /* Osc/128 prescaler */
>            ASSR = _BV(AS2);
>
>     Doesn't this attach the timer clock to TOSC pin(s)?
>
>            TIMSK2 = _BV(TOIE2);    /* enable overflow interrupt */
>
>         However no interrupt was generated.
>         What did I do wrong?
>
>     Are you setting the global interrupt flag? sei()
>
>
>         -- 
>         Ori Idan
>
>     Are you wanting to run the whole micro from the 32K crystal, or
>     just the timer?
>
>     Regards
>     Neil Davey
>
>
>
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>
>
>
> --
> ספרים וסיפורים שכתבתי: http://www.thestories.org 


--
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Neil Davey
Griffith University

Centre for Wireless Monitoring and Applications
Griffith School of Engineering
Nathan Campus
Phone: 07-3735-7008
Fax: 07-3735-5112

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