PCI Interrupt and Acknowledgement

["I. Servan Uzun" <isu@btae.mam.gov.tr>]

Hi,

I am using Altera' s 64-bit 66MHz PCI Megacore in my project.
I implemented an interrrupt & acknowledgement logic as follows,

    1-) When the process is completed, an interrupt signal is
generated and fed to pci megacore function.
    2-) When my software that is running on the computer catches the
pci interrrupt, it sets a predefined bit of a register (in fpga) in order to
acknowledge the interrupt.
    3-) When I check this timing by a logic analyzer, I found that it is
8 microseconds between the rising edge of the interrupt signal and the
rising edge of int-acknowledge signal. This means that it takes 8 usec
to acknowledge the interrupt.

My question is that is this time is normal or long? Is it possible to
shorten
this interrupt acknowledgement time?

Thanks in advance.

- Servan