Software- to- PCI design communication.

Hi, please guide me on two beginner-level questions.

A program writes an integer onto BAR0 on the Stratix PCI board. I wish the fpga design to read this value from BAR0, and store it (and display the last 8 bits on the LEDs on the board).

1. How do I trigger my design whenever something is written onto BAR0?

1. How can I read from BAR0 from my verilog design?

Thanks a lot,

Mohit