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Discussion Groups | AVRclub | Fuses (was Re: [AVR club] Digest Number 407)
Atmel AVR Microcontroller discussion group.
Fuses (was Re: [AVR club] Digest Number 407) - Graham Davies - Sep 16 12:29:00 2004
--- In avrclub@avrc..., Wade A Smith <warm38@j...> wrote:
> ... what is the correct way to set
> the fuses so I can still use the AVR.
If you are talking about the clock fuses, this depends on the clock
source you want to use.
> The STK500 came without a crystal, so
> I ASSuME that I should use an internal osc?
OK, I think I see your problem. With the STK500, you cannot use a
crystal directly connected to the MCU for reasons explained in the
STK500 User Guide. What Atmel have done is provided an external
oscillator to which you can plug in the crystal of your choice. Even
though you are using a crystal, you have to program the clock select
fuses for an external oscillator. Please verify this before acting on
it as I am working from memory.
Graham.
(You need to be a member of avrclub -- send a blank email to avrclub-subscribe@yahoogroups.com )
> ... what is the correct way to set
> the fuses so I can still use the AVR.
If you are talking about the clock fuses, this depends on the clock
source you want to use.
> The STK500 came without a crystal, so
> I ASSuME that I should use an internal osc?
OK, I think I see your problem. With the STK500, you cannot use a
crystal directly connected to the MCU for reasons explained in the
STK500 User Guide. What Atmel have done is provided an external
oscillator to which you can plug in the crystal of your choice. Even
though you are using a crystal, you have to program the clock select
fuses for an external oscillator. Please verify this before acting on
it as I am working from memory.
Graham.
(You need to be a member of avrclub -- send a blank email to avrclub-subscribe@yahoogroups.com )
Re: Fuses (was Re: [AVR club] Digest Number 407) - Zack Widup - Sep 16 13:10:00 2004
On Thu, 16 Sep 2004, Graham Davies wrote:
> --- In avrclub@avrc..., Wade A Smith <warm38@j...> wrote:
>
> > ... what is the correct way to set
> > the fuses so I can still use the AVR.
>
> If you are talking about the clock fuses, this depends on the clock
> source you want to use.
>
> > The STK500 came without a crystal, so
> > I ASSuME that I should use an internal osc?
>
> OK, I think I see your problem. With the STK500, you cannot use a
> crystal directly connected to the MCU for reasons explained in the
> STK500 User Guide. What Atmel have done is provided an external
> oscillator to which you can plug in the crystal of your choice. Even
> though you are using a crystal, you have to program the clock select
> fuses for an external oscillator. Please verify this before acting on
> it as I am working from memory.
>
> Graham.
Yes, this is correct. I've used it several times with 10, 12 and 16 MHz
crystals instead of the built-in 3.69 MHz oscillator on the STK500 system.
Zack
(You need to be a member of avrclub -- send a blank email to avrclub-subscribe@yahoogroups.com )
> --- In avrclub@avrc..., Wade A Smith <warm38@j...> wrote:
>
> > ... what is the correct way to set
> > the fuses so I can still use the AVR.
>
> If you are talking about the clock fuses, this depends on the clock
> source you want to use.
>
> > The STK500 came without a crystal, so
> > I ASSuME that I should use an internal osc?
>
> OK, I think I see your problem. With the STK500, you cannot use a
> crystal directly connected to the MCU for reasons explained in the
> STK500 User Guide. What Atmel have done is provided an external
> oscillator to which you can plug in the crystal of your choice. Even
> though you are using a crystal, you have to program the clock select
> fuses for an external oscillator. Please verify this before acting on
> it as I am working from memory.
>
> Graham.
Yes, this is correct. I've used it several times with 10, 12 and 16 MHz
crystals instead of the built-in 3.69 MHz oscillator on the STK500 system.
Zack
(You need to be a member of avrclub -- send a blank email to avrclub-subscribe@yahoogroups.com )