I am trying to communicate a 89c52(master) with a 89c2051 (slave) using i2c interface? There are also other i2c devices on the same lines.
there they have given the multimaster routines for 89c751/52 which have inbuilt i2c registers. But not for 89c51 or 89c2051.
Where in your original post does it say multimaster ?
What is my problem is how should I detect start condition of the communication?
Tie SDA to an interrupt pin

Erik