Hi Agustin,

I know nobody, which implements an I2C slave
on the C51 or C2051, since many times to slow.

So the both examples use always 51 derivates with build in I2C hardware.
You need a high speed micro, e.g. Scenix SX to guarantee
the 100kHz I2C speed.
I think, you can also use the AVR for up to 50kHz.
And the C2051 with a 24MHz crystal for up to 20kHz.


Peter