[Tinyos-help] atmega128 clock frequency

[Giri Baleri]

A more comprehensive description of various fuse bytes is available in
Appendix B of the XMesh manual below.
http://www.xbow.com/Support/Support_pdf_files/XMesh_Users_Manual.pdf

A low fuse byte value of 0xc4 would set it to internal oscillator. I
think the ATmega128's internal RC oscillator can provide a fixed 1.0,
2.0, 4.0, or 8.0 MHz clock. 

Giri

-----Original Message-----
From: Michael Schippling [mailto:schip at santafe.edu] 
Sent: Tuesday, July 17, 2007 10:17 PM
To: Giri Baleri
Cc: roberto pagliari; tinyos-help at Millennium.Berkeley.EDU
Subject: Re: [Tinyos-help] atmega128 clock frequency

whew...now I don't have to go look up the config bytes...
Is there an internal osc that will run faster than the xtal?

And are we certain that the config is really all 0xff?
That sounds too conveniently like a read error...

MS


Giri Baleri wrote:
> The low byte value of 0xff indicates that the ATmega128 is configured 
> to use external oscillator. The frequency of the external oscillator 
> is normally 7.3728 MHz.
>  
> Giri
> 
> ----------------------------------------------------------------------
> --
> *From:* tinyos-help-bounces at Millennium.Berkeley.EDU
> [mailto:tinyos-help-bounces at Millennium.Berkeley.EDU] *On Behalf Of 
> *roberto pagliari
> *Sent:* Tuesday, July 17, 2007 3:27 PM
> *To:* schip at santafe.edu
> *Cc:* tinyos-help at Millennium.Berkeley.EDU
> *Subject:* Re: [Tinyos-help] atmega128 clock frequency
> 
> my actual configuration, running
> uisp -dprog=data -dpart=ATmega128 --rd_fuses
> 
> gives me the following
> fuse low byte  0xff
> fuse high byte 0xff
> fuse extended byte 0xff
> calibration byte      0xff - read only
> lock bits  0xff
> 
> BLB12 -> 1
> BLB11 -> 1
> BLB02 -> 1
> BLB01 -> 1
> LB2     -> 1
> LB1     -> 1
> 
> so, is it 7.3Mhz?
> 
> On 7/17/07, *roberto pagliari* <bobtinyos07 at gmail.com 
> <mailto:bobtinyos07 at gmail.com>> wrote:
> 
>     my fuse low byte is set to 0xff. this means the clock frequency is
>     7.3Mhz (not 8Mhz) right?
> 
>     thank you in advance
> 
> 
>     On 7/17/07, *Michael Schippling* < schip at santafe.edu
>     <mailto:schip at santafe.edu>> wrote:
> 
>         I think "change the crystal" is the only answer for the
ATMEGA.
>         It's sounds like the MSP can be overclocked in software
though.
>         MS
> 
>         roberto pagliari wrote:
>         >  how can I set the clock frequency of motes microcontroller?
>         >  I'm using micaz mote right now
>         >
>         >
>         >
>
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