PCI Design Using SOPC Builder

hi, guys. now i am busying with PCI IP usage. i want to design a PCI Device to transfer data to the PC. In the SOPC Builder, i have built a small model. It contains a PCI IP (Target mode), and a on chip ram(128k).

Because the Altera PCI IP provides the Testbench, so i use this testbench to simulate in Modelsim. But during simulation, i found that:

when i try to read more than 8 Dword from the Ram, it wil pop up : the target disconnected without of data. while for burst writing, the length can be any you want.

what's the problem?

any suggestions about the PCI desing, PCI IP usage are welcome.

thanks in advance! http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/blink.gif