How to changing 2343 internal rc frequency?

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Hello,

is there anyone who could tell me how to change the internal oscilator frequncy of the at90s2343 ?
Its seems to be fixed at 1 MHZ but in the manual i readed about a wide range up to 10 MHZ!
How an i change the standard value?

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I think you read that wrong. The internal oscilator is fixed at 1Mhz, but if you use an external one you can go up to 10Mhz.

Dave

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...and in order to enable the external oscillator, you must unprogram the RCEN fuse. The effect is not discernible until the next power-on reset.

Best regards,

Morten, AVR tech. support, Atmel FAE

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Thank U! I have read it wrong, is there a Prozessor in the Atmel Family wich provides several internal oscilator speeds?

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Yes there is, almost The new ATmega163 ha an onchip oscillator that you can calibrate. But you can't change the value very much. And if you do, you must change the write times at programming of FLASH and EEPROM. Note that the internal ceramic oscillator (as the one you use in the 2343 and 163) is very sensitive for supply voltage. At 3V it runs at about 340 kHz (wich will lower the supply current even more).

/Bengt

My favorites:
1. My oscilloscope, Yokogawa DLM2024.
2. My soldering iron, Weller WD2M, WMRP+WMRT.
3. JTAGICE3 debugger.

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Bengt is right,

supply voltage can heavly influence internal osc speed. To get the maximum limit for 2343 you can apply a diode (1N4007 can be good) with cathode to GND access on your PCB. It will rise the supply about 0.5V giving 5.5V if you are using a 78x05 regulating your supply.
If you rise this limit 2343s can blow. In my experience at 5.5V drives the internal osc about 1.5-1.8MHz, max 2MHz. At any rate this make speed floating. I can't love it.

Fabrizio