Hi Frederic,

i am testing geerts new i2c code tonight, i have a few mega32s lying
around, so if you could provide me with the atmel source you are using,
i would like to do some testing during the week. maybe we can add an
option for a "run i2c in slow mode"

John



On 07.01.2007 at , you wrote:
> Hello,
>
> My fox board is flashed with the Phrozen distro.
>
> I am using the I2C kernel driver to communicate with a remote ATMega32
> micro-controller.
>
> When running in slave mode, the ATMega32 datasheet states that the
> microcontroller clock frequency must
> be at leat 16 times the i2c clock frequency.
>
> I looked at the i2c clock signal delivered by the fox board, and saw
> that the i2c clock frequency delivered by the Fox (ie the
> kernel i2c driver) is about 1.2 MHz.
>
> Do you think that this value is correct ? (I may have make some
mistakes
> during my measurement)
>
> My ATMega32 is running at 8 MHz (because I dont want to use an
external
> crystal oscillator: 8 MHz is the maximum clock
> frequency using the internel RC oscillator).
>
> It means that the fox i2c deliver a too quick signal (1.2 x 16 = 19.2
Mhz).
>
> So the question is: how can I slow down the clock signal ?
>
> I tried to increase CLOCK_LOW_TIME / CLOCK_HIGH_TIME in
> cris/arch-v10/drivers/i2c.c. Is this the right way
> to achieve this ?
>
> Thank you !
>
> Frederic.
>
>



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