altera Flex10k + I2C

[Marc]

hi,
I implemented an I2C-bus part in my Flex10k where the SDA line is bidir and
the SCL is input (slave mode). Clock input is 24MHz (not SCL).
What I see on the SDA pin of the device is that the signal there is
oscillating with frequence of 1.3Hz.
It doesn't matter when this line is floating or connected to a I2C
transmitter in master mode by use of a pull-up resistor.
The transmitter is OK I checked.

Any help?

Marc