Memory mapped IO

JWK
Hi!

I want to add a PCA9556 parallel to I2C chip to my mini2440 to get a second
and faster I2C bus (Linux driver for that chip on ISA bus are available).
Which adress space do I have to use for that? Hope somebody can help me. Is
there a CSx-signal onboard or do I need an adress-decoder?

Thanks,

Jan